Tree hollow

A tree hollow or tree hole is a cavity in a tree. Such hollows naturally form in the branches or trunks of many kinds of trees. They provide a habitat to animals, such as owls. Hollows in the trees also appear under the influence of water, fire, wind, lightnings and living beings, such as rodents, mammals (it can take centuries to form the hollow fit enough for the big mammal), birds, some bacteria and fungis.

This short article about biology can be made longer. You can help Wikipedia by adding to it.