Squirrels live in nests called “dreys” that they build which are made of twigs and leaves. The inside of their nests are lined with soft materials such as feathers for comfort. Squirrels usually build their nests high in a tree between two strong branches. The nests are high enough so that they are protected ground predators, but not too high or the nest will be destroyed by the winds. Squirrels will also build their dens in a hollow tree cavity.