Science

With cold soup, the fault may not be in the salt but in the absence of heat to volatilize the other flavorings so they ascend to the nose. Flavor is both taste and smell, and most spices are also perceived with the nose, so that the perceived concentration increases as the volatiles, the gaseous form … Read more

Cans of spoiled food may swell, and it is usually taken as a sign of spoilage, but canned food may be spoiled even if the can does not swell. If cans do swell, it can be for two reasons, one chemical and one biological. Acid foods, like tomato juice, canned pineapple or almost any canned … Read more

The change in color in a green pepper is the same kind that occurs in any other ripening fruit that changes color. Chlorophyll breaks down or degrades, and other pigments are exposed or formed. The complex ripening process is under the control of plant hormones like ethylene, a growth regulator that makes chlorophyll break clown, … Read more

Peaches spoil faster than fruits like apples or pears for several reasons. First, they have a different surface structure, with no natural waxy coating or thick epidermis to protect them from bruises. Second, unless a fruit is completely dried out, normal metabolism continues and the fruit burns up sugar reserves; the peach respires at a … Read more

It might be difficult, but it is not impossible for the child of strict vegetarians to get enough calcium from a diet that does not include eggs, meat, fish or milk products. The recommended daily allowance of calcium for children is 600 to 1,000 milligrams, depending on age. Many fruits and vegetables contain significant and … Read more

Any vitamin or mineral taken in excess could interfere with the absorption, metabolism or storage of some other component of the diet, but interactions are usually not a problem. Nutritionists basically recommend that people should derive their nutrition from food, not food supplements, and that they should choose a well-balanced diet including a variety of … Read more

The problem is oligosaccharides, or “several-unit” sugars, which are produced by legumes, especially in the final stages of seed development. The oligosaccharides, called raffinose, stachyose and verbascose, are used by the seeds to store energy. The human body lacks enzymes to break them down, and so cannot digest and absorb them as it does the … Read more

Vitamin E is an antioxidant, interfering with the chemistry of oxygen interacting with other chemicals. Both human bodies and food are degraded by oxidation, so the same chemistry that helps protect humans can protect foods. Vitamin E is a broad term for a member of a group of chemicals called tocopherols, which have vitamin E … Read more

Gelatin is a tasteless, odorless substance extracted by boiling collagen, a jelly-like fibrous protein found in animal bones, tendons, hoofs and connective tissues. When dried gelatin is mixed in warm water, the fine-grained particles do not actually dissolve, but rather become evenly dispersed and remain suspended in the liquid. When cooled to 95 degrees Fahrenheit … Read more

Spinach often grows well in sandy soil, and unless it is very well rinsed it may feel gritty. Spinach contains some oxalic acid. Rhubarb, which is sour enough to set your teeth on edge, owes its sour taste to oxalic acid, which can be gritty. However, the variety of spinach that accumulates the most oxalic … Read more

It is possible to get a toxic dose of vitamin A, but not from carrots. Probably the worst thing that would result from eating a large number of carrots is an alarming-looking yellowing of the skin called carotenemia. It is apparently harmless. Carrots contain an orange pigment, called beta carotene, that the human body converts … Read more

Some but not all vitamins are lost in cooking, and the amount varies widely. Minerals are fairly stable in cooking, but different vitamins are susceptible in different degrees to various factors, including heat, light and air. Generally, water-soluble vitamins like riboflavin, thiamine and especially vitamin C are more susceptible to losses in heat and water … Read more

The waxy film or coating on fruits and vegetables is a natural protective substance secreted by cells in or near the skin of the fruits. Composed of many kinds of waxes and lipids, the film helps waterproof the fruit. It prevents cracking because of moisture loss and also prevents moisture from entering the fruit from … Read more

Storing eggs small end down keeps eggs fresh somewhat longer. An egg’s freshness is judged by candling, using a light to see the position of the yolk. The nearer the yolk is to the center, the fresher it stays, because the surrounding albumin, or egg white has antibacterial properties to protect the embryo, or the … Read more

Varieties of fruits and vegetables can differ widely in nutrition. For example, a New York State McIntosh apple would have about 3 milligrams of ascorbic acid, or vitamin C, per 100 grams, while a Cortland would have 11 milligrams, a Jonathan would have 17 and a Cox orange would have 19. One kind of winter … Read more

Tonic water, also known as Indian tonic water, is a carbonated soft drink with dissolved quinine. The amount of quinine in tonic water would not be much help against its original target, the fever of malaria. Quinine, derived from the bark of the cinchona tree, must be administered in very high doses to reduce fevers. … Read more

A person who can taste the very few molecules of plasticizer that might escape from a food container probably has an extra-sensitive sense of taste but need not worry about being harmed. The plasticizers used to make the plastics flexible in containers intended for food are very slightly soluble in water and slightly more soluble … Read more

The National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health estimates that alcohol is cleared at a rate of approximately one hundred milligrams per kilogram of body weight per hour. That’s about half an ounce of pure alcohol every two hours. So if a person ingested approximately three drinks in a … Read more

Kudzu, often called the vine that ate the South, is a Chinese and Japanese fodder and cover crop with an edible root. The original Japanese pronunciation was kuzu. The Latin name is Pueraria lobata, but it was called Pueraria thunbergiana until 1947. An American consul in Japan in the late nineteenth century, Thomas Hogg, exported … Read more

Popcorn pops because of a delicate balance between a moist interior and a dry coating. The exterior cells, the pericarp, are hard and relatively impermeable. The interior cells are soft and contain moisture. When the seed is heated, the moisture turns to steam. The pressure builds up to the point where the hard outside pops, … Read more

Don’t count on either safety or succulence when it comes to white mushrooms in the woods. It is probably a harmless but not so tasty mushroom, but the squirrel is probably no better judge of its safety than a layman. The squirrel’s physiology is close enough to ours that if a mushroom is deadly to … Read more

Most experts say it is possible for ivy to damage walls both physically and chemically. But botanical gardeners usually advise that the chief danger is to masonry that is already in bad shape. There are two schools of thought. One sees ivy as a likely threat to a wall. The other believes that if the … Read more

Water and dissolved minerals are taken up through cells called the xylem, and food manufactured in the leaves is distributed to the rest of the plant through cells called the phloem. The rise of sap is essentially concerned with the xylem. It is a system of very fine tubes that continuously connect the extremities of … Read more

Many tress along the street don’t live very long. The average life of a street tree surrounded by concrete and asphalt is seven to fifteen years. Many do survive, but decline rapidly. Many factors underground determine whether a tree will make it. If the soil is so compacted that the roots can’t get in, it … Read more

Oleander is extremely toxic, one of the most toxic plants on anyone’s list. Even a few oleander leaves falling into a small ornamental pool could poison a dog who lapped water from the pool. All parts of the oleander plant are considered toxic, with the seeds usually the most toxic, the leaves a little less … Read more

There are several types of poison associated with different kinds of poisonous mushrooms. The chief mechanism is the destruction of the liver, the filtering system for poisons in the body. The toadstool toxin inhibits an enzyme called RNA polymerase, which synthesizes the genetic material messenger RNA. Without the messenger KNA, the liver cells stop synthesizing … Read more

Sometimes there are nice correlations between an organism’s defenses and its enemies, but in the case of poison ivy, any such connection is a puzzle. Poison ivy is toxic to humans and a few higher primates and that’s it. As close a relative as the rhesus monkey, for example, is normally not sensitive to it. … Read more

It is possible to grow a coconut palm from a coconut, if it is an unhusked coconut. The ones usually sold as food have had their tough fibrous outer coating removed. The hairy kernel of Cocos nucifera encloses an insignificant embryo amid a large endosperm of meat and liquid. An unhusked coconut, still filled with … Read more

A tall palm tree called Lodoicea maldivicia, which grows only in the Seychelles in the Indian Ocean, produces the largest single seed in the world known in the plant kingdom. The two-lobed seed can be twenty inches long. It grows in huge fruits that look something like two coconuts joined together in an almost heart-shaped … Read more

All plant functions, from germination to photosynthesis to blooming, can be accomplished under light in wavelengths ranging from 300 to 700 manometers, or billionths of a meter. Therefore, indoor gardeners need either incandescent “grow lights” or a combination of “cool” and “warm” fluorescent bulbs that give off light in that range. Regular incandescent lights give … Read more

Viruses attack living cells like soldiers taking over a factory. The processes a plant relies on to survive, like growth, metabolism and photosynthesis, take place in cells. Viruses can subvert the cells’ functions to their own ends, eventually killing the tissues that the cells make up. First, the virus attaches itself to the external wall … Read more

Strings of lights do not harm a tree unless it is brought inside in a pot and exposed to warm dry air and then suddenly taken back outside into the cold, or unless the lights are actually hot enough to cause burns. Light does affect the growth cycle of trees, but chiefly in combination with … Read more

Honeybees collect the nectar secreted by flowers to attract pollinating insects and convert it to honey through two chemical changes and one physical change. The changes add up to a product that is digestible by bees or humans, easy for the bees to store and free of microorganisms that can cause spoilage, like bacteria or … Read more

The leaf color changes of autumn result from a complex interplay of factors of temperature, sunlight and moisture, all dependent on timing. Not all the processes are predictable, but it is known that sunny days and cool nights in late summer and early autumn make for a particularly bright display of reds. The yellow display … Read more

The deer tick, which often carries the Lyme disease microbe, requires very humid surroundings and would probably not survive longer than forty-eight hours in the dry air of a house. The deer tick belongs to the hard-bodied tick group, but certain other kinds of ticks can live for long periods under adverse conditions. Deer ticks … Read more

Beeswax is secreted by four pairs of glands under the abdomen of worker bees. It has more than two hundred chemical components. Most are fairly high molecular-weight hydrocarbons similar to a plastic. The wax is naturally white and is stained by the pollen, gums, resins and other things that bees collect. Beeswax is akin to … Read more

In terms of weight in comparison to volume, flies don’t weigh much, so very little force is required to keep a fly from falling. That force is exerted by structures on the tarsi, the tips of the fly’s legs. First, there is a set of claws, which can be seen with a very good hand … Read more

Cobwebs are made by spiders. The word “cob” is derived from the Middle English word for spider, coppe, and cobweb is often used to refer to any spiderweb. The dusty strings that do not look like the circular Halloween spiderwebs, which are made by only some species, are instead probably an accumulation of abandoned draglines. … Read more

Insects have muscles and they are extremely strong. An insect can lift twenty or more times its body weight, while most people can lift their own weight or a little more. Insects have their “bones” on the outside, but the attachment points for muscles are on the inside. The muscles are linked to little inward … Read more

Some moths do eat wool and digest the fibers, especially if the wool is soiled. They can also damage synthetics, though they get no nutrition. However, the two main species of clothes moths, the case making moth and the webbing moth, are unjustly blamed for holes in sweaters caused by carpet beetles, which are probably … Read more

Mexican jumping beans, actually seeds of plants in the Croton family, are invaded by larvae of a moth, Cydia saltitans, and it is the larvae that make the beans move. The larvae are aroused by the warmth of someone’s hand, making the “beans” jump. The insect, commonly called the Mexican jumping bean borer, is native … Read more

Many adult flies die off with the arrival of cold weather, but others live through the winter. Among these flies are cluster flies, so called because of their habit of clustering. They are relatively large flies, and are not from the same family as houseflies, but they also like houses, and are probably the ones … Read more

The three dots on the insect’s head are the simple eyes, or ocelli. Many insects have both compound and simple eyes. A compound eye is the familiar faceted bulge on the fly, for example, but a simple eye is just one little hexagonal surface. They are not believed to generate an image, though we do … Read more

Snow Fleas are not fleas, but tiny insects of several species that thrive on glaciers and snowbanks, feeding on even smaller specks of plant debris. A common North American species, also found in Europe, is also called a scorpion fly. It is only about a tenth of an inch long. Wings are vestigial or missing, … Read more

Significant pollination of many plants is done by butterflies and moths, sometimes exclusively, and they are not the only animals other than bees that work at pollination. Bees of various kinds, especially honeybees, and other social insects are the most familiar and important pollen carriers. However, beetles, moths, butterflies and flies are involved in pollinating … Read more

Swarms of ants in their reproductive stage often make an appearance in July. Some ants, both males and females, or queens, have wings at mating time, and July is a time when several species would be flying. Termites would be more likely to swarm in spring or fall. As for what they wanted, inspect the … Read more

Katydids have call-and-response sessions and feed on tree foliage, but they will not do trees tremendous harm. Katydids and cicadas have different sounds and schedules. The male katydid, a relative of the cricket, does its chirping beginning at dusk in the mating season, which is early fall. It is a distinctive three or four-part call, … Read more

There is a group of spiders sometimes called cannibal or pirate spiders, members of the family Mimetidae, that feed on other spiders, creeping into their webs and killing them. Many authorities believe the pirates never spin their own webs and feed exclusively on other spiders. The black widow spider is comparatively abstemious, with the female … Read more

Usefulness is a subjective term, but wasps, which with bees and ants make up the order Hymenoptera, are extraordinarily well adapted to certain human ends. Almost all are predators or parasites of injurious pests, and some act as pollinators of valuable plants. With varying degrees of success, wasps of different species have been bred, imported … Read more

Some insects roll over on their backs when they die, some don’t, and some may not be dead at all. Collectors usually do not find many dead insects in the field, because they are so quickly scavenged by other creatures. As for what position they end up in, it depends on the shape of the … Read more

Lovebugs are best known for their nuptial flight, and are Bibionid flies of the species Plecia nearctica. They come out in huge numbers, emerging in a synchronized fashion twice a year, especially in fall, when the clouds of them are so thick they impair driving visibility. They fly around with the tips of their abdomens … Read more

Cats, like many other animals, have an extra olfactory organ, called the vomeronasal organ or Jacobson’s organ, that helps them sense scents and excretions from both other cats and their prey. The organ is very well developed in some animals, like reptiles, and almost vestigial in humans. In cats, it is a pouch above the … Read more

The best evidence indicates that all modern dogs are descended from an ancestral wolf species. Darwin originally thought dogs were so diverse that they must have been descended from more than one form. And Konrad Lorenz, the expert on animal behavior, popularized the idea that dogs like huskies and German shepherds were descended from wolves, … Read more

Insects definitely see colors, smell and sometimes hear, but not the way people do. Our eyes see a we range of wavelengths, but many insects have vision tuned into a specific range to find resources like food and shelter. For example, because of filters in their eyes, quite a few insects see leaves as yellow, … Read more

A dog’s tongue is not cleaner than a person’s, and judging by the things they lick, it may not be as clean. Dogs, like people, harbor various kinds of germs in their mouths, and dogs tongues have no special antiseptic properties. Different species of animals do have different levels of resistance to the many different … Read more

Whether it’s a dog, cat, human or cow mouth, they are all probably pretty similar in terms of cleanliness or dirtiness. It’s certain that there’s not a whole lot of difference as far as bite wounds are concerned. Mouths contain germs that can cause infections, and it would be dangerous for a child to bite … Read more

A litter of kittens have more than one father, and so can a litter of puppies. In fact, any of the species that have litters and can be bred multiple times during one heat cycle can have offspring with different sires. The scientific term for such breeding is superfecundation. Female cats are induced ovulators and … Read more

The question of potential animal longevity is complicated even among pets by the fact that many dogs and cats do not live an entire life span, because of trauma and euthanasia. The Animal Medical Center in New York asked animal medicine experts from around the nation at what age they consider pets to be geriatric. … Read more

Cats cannot see in total darkness, but they require much less light than people and some of the animals they hunt because of the structure of their eyes. A cat’s pupil is a vertical slit when it is constricted and becomes a large round or oval when it dilates. The slit-shaped opening protects the eye … Read more

A vegetarian diet for cats would be difficult to the point of impossibility. A vegetable-based diet could be devised, but only if some chemical reagents and animal fats were added to it. That is because cats cannot synthesize some of the essential fatty acids found in animal fat. For example, plants have virtually none of … Read more

Most researchers agree that a cat’s purr results from vibrations in the muscles of the larynx and in the diaphragm. That’s why you can feel it both in the throat and down in the stomach. Purring, which is limited to the common domestic cat, has also been described by some as resembling human snoring, with … Read more

Unfortunately for the neighbors, barking for hours puts no more strain on dogs than normal conversation does on people. We tend to think of the bark as so atonal that it sounds like the equivalent of a human scream. If we made such a sound, we would be hoarse in five minutes. But the dog … Read more

The kneading motion with the forepaws is often done when the cat is in a pleased or expectant mood. It probably imitates the kneading of a mammary gland by a nursing kitten, stimulating the release of milk from the mommy cat. The behavior is also called milk-treading. However, there are also scent glands on the … Read more

Two things makes chocolate dangerous to dogs. The first is the worst, a chemical called theobromine. The second is rather high levels of caffeine. A small amount of chocolate is unlikely to cause much harm, but in large amounts theobromine can be very dangerous. Eating an entire box of chocolates is more dangerous to a … Read more

Scientists would find it difficult and perhaps pointless to try to prove an explanation, but can make some educated guesses. All canids, that is, wolves, coyotes, dogs, etc., typically circle before they lie down, though not every single member of all species will do this. The old assumption was that it was to stamp down … Read more

Sheep can swim, but only in dire circumstances. The ability is basically instinctive, and a life-saving device. They don’t go swimming every day, but in case of flooding, or falling into a river, in essence they know how to swim. Sheep have never been known as big swimmers, and most of the habitat where they … Read more

First, it is a legal requirement to vaccinate pet cats in many states. Second, there aren’t any cats that never go out, there are only cats that aren’t supposed to go out. Eventually, any cat leaves the safety of home to visit the veterinarian, to be boarded, to leap or fall out an unguarded window, … Read more

The dog’s wet nose is relatively misunderstood by many pet owners. A dog with a wet nose is not an invariable indicator of health, good or bad. It is normal for a dog to drain some fluid out of the nose, and the nose may be wet and cold because of evaporation. And it is … Read more

Tail motion and eye contact are parts of a complicated inborn system of communication among dogs. The signals let dogs figure out who is top dog in a group or when meeting a stranger. They can also communicate emotional states. Tail wagging may simply indicate excitement. Position is important, too. The tail held high is … Read more

The active ingrediant of catnip, Nepeta cataria, is a chemical called nepetalactone that sets off in the cat’s brain the behavioral patterns usually connected with a variety of pleasurable or exciting things. The playing, hunting, feeding or sex neurocircuits are randomly triggered, in no particular order. Lactones are chemicals present in certain body substances, like … Read more

The definition of dreaming can be quite different for animals, and obviously you cannot ask an animal if it has had a dream. But experts cite strong suggestive evidence that mammals like dogs and cats experience something people would recognize as dreams. Such animals have the same brain processes during sleep as humans. They experience … Read more

The common aquarium goldfish, Carassius auratus, can live thirty years or more under ideal conditions. An aquarium limits their size, but a pond lets them achieve their maximum growth. Some goldfish can reach up to two feet in length. Goldfish often change color as they age and develop their full color patterns. In fact, one … Read more

It is not as simple as seeing whether a bull charges a red cape, scientists say, and some of the evidence is indirect. Indirect research methods include examining the behavior of the animal in its natural world. One way is simply to look at whether the animal itself has colors. You can assume that if … Read more

There have been many mass extinctions over the millions of years since life began, each sparing a remnant of living things. Survivors of the extinction that killed the dinosaurs tended to be widespread, adaptable and, perhaps most important, small, paleontologists say. There are many theories about exactly why the dinosaurs died and over what period, … Read more

Animals do get tooth cavities, and for the same reason that people do, even without a sweet diet. Bacteria build up on the teeth and cause decay, although they may be different bacteria from the ones that cause human cavities. It is recommended that most pets including dogs and cats have their teeth cleaned. In … Read more

Male Emperor Penguins build up big fat reserves before nesting and slowly burn them off. At fifty or sixty pounds or more, emperors are the largest penguins, and their size means they can withstand cold better than smaller species and can “nest” the farthest south. They breed on the frozen Antarctic Sea, where temperatures may … Read more

There are plenty of dead pigeons around, if you look carefully, but there are lots of things around that clean them up, scavenging animals of all sorts, including rats, and even gray squirrels. Insects probably do not have a major role in pigeon disposal. It might take a week for the various carrion beetles to … Read more

Birds are known to use a combination of things, including landmarks, the angle of the sun, stars, odors, even the magnetic field of the earth, as they migrate. However, scientists still do not know exactly what they use for a map and compass, let alone exactly how they use them. A flock of birds, for … Read more

A number of authorities agree that birds do not get any special storm warnings before a hurricane that allow them to avoid it. In fact, bird-watchers find that oceanic birds often fly before the winds of a hurricane and end up far from their tropical homes. For example, sooty terns may be swept from Florida … Read more

The key to a birdhouse is not a manufacturer’s custom design but a simple box of the proper size. If you put up nest boxes of the proper dimensions, you will typically get a wren or a chickadee; a flicker or a red-bellied woodpecker; a screech owl; and perhaps a titmouse, for a usual maximum … Read more

Unless you live on a farm in the middle of Nebraska and the nearest house is thirty miles down the road, birds do not become dependent on you as a sole source of food. Birds come to feeders for supplemental food. They prefer to eat natural food, and given the choice between ant steak and … Read more

The gestures that birds make when they put dust on their feathers and then shake and preen it off look like the movements they make when bathing in water, but the purpose is not exactly the same. Birds take dust baths to rid themselves of all sorts of parasites that crawl in and between their … Read more

First of all, they are gulls, not sea gulls. “Sea gull” is something of a misnomer, while these birds were mostly coastal in the past, there have always been some inland. Now, many gulls’ habitats have shifted inland, primarily because they like to scavenge in garbage dumps. They will eat almost anything, making them goats … Read more

Birds often do reuse their nests, not always and not all birds. But the phoebe is a perfect example of a species that uses the same nest from year to year. It is usually the same pair of adult birds, but if misfortune happens to one, the other will probably find a new mate and … Read more

Birds have a sort of thin extra eyelid called a nictitating membrane that protects their eyes and may do so in the rain. The membrane is not entirely transparent, so the birds may not see clearly, but they can probably see light and dark. As in cats, dogs and other animals, this membrane can flick … Read more

The wandering albatross is often listed as the longest-living bird in the wild, but it is not known exactly how long its life span is. The information from bird bands returned to ornithologists indicates that both royal and wandering albatrosses, the two largest species, are around for at least forty years. Ornithologists know they live … Read more

Some birds do hit branches when they fly, but most are very maneuverable. Birds also have excellent vision, and the flight pattern and style, musculature and aerodynamic characteristics, and even how fast they fly, are adapted to the environment in which they fly. Birds that live in the forest and fly through the canopy are … Read more

Birds don’t have to work at not falling off their perches when they sleep. Tendons on the bottom of their feet, called flexor tendons, respond to pressure from a branch or other perch by causing the toes to wrap around the perch automatically. Humans would have to expend energy to hold on, but birds would … Read more

Pigeons, or rock doves, are actually fairly common in agricultural areas. There they find niches in barns and lofts that resemble the rocky ledges that are their natural nesting sites, as well as plentiful supplies of their favorite food, small grains. However, pigeons do seem to prefer cities to small towns and wilderness. There are … Read more

They have an extremely good sense of hearing. For example, the hairy woodpecker and pileated woodpecker can actually hear those carpenter ant larvae and get right into a nest of them quite efficiently. Woodpeckers also tap tree trunks to find the hollow places where insects might be.