Not all birds build nests in trees. Certain birds wouldn’t even consider building a nest in a tree.
There are quite a few birds that nest in underground burrows and cracks in rocks. Birds that like this type of home often use the abandoned tunnels of moles and rats.
Some birds that will nest only on the ground, either in the forest or in meadow grass. Birds like the catbird and warbler prefer homes in low shrubs or trees. Certain of these tree and shrub dwellers build their nests on the outer branches of evergreens.
Other birds will build nests only in marsh areas and a few others will use dead trees.
Barn swallows and cliff swallows like the houses, barns, and sheds people build. Some wrens have been known to nest in the pockets of clothing left hanging out of doors.
Keep your eyes open when you go for a walk in the country, for you can never tell where you’ll find a bird’s nest.