There is no record of it ever having rained cats and dogs, but it has rained FROGS. How can this happen?
A whirlwind passing over a river or lake, where frogs mate, may scoop up their fertilized eggs and carry them along in the air for a distance. While the eggs are being whirled along in the atmosphere, they are hatching into tiny, tailed animals known as tadpoles.
Then, when the wind has spent itself, whatever is in the air falls to the earth. In this case, it’s a shower of tadpoles, or baby frogs.
Two other animal storms are on record. In August, 1892, in Padeborn, Germany, there was a snail storm, and in July, 1972, black worms about the size of bees fell from the sky by the thousands over Bucharest, Romania.