A tree hollow is like a little house or apartment for animals that live in trees. Some trees have holes in them that are big enough for animals to climb into and make their home. These trees become really important for animals because they provide a sheltered place to stay warm and safe.
Many different animals use tree hollows as homes. Birds, like owls and woodpeckers, use tree hollows to build their nests and lay their eggs. Squirrels and some small mammals, like raccoons and possums, also use tree hollows to live in.
Sometimes, tree hollows are made naturally by the tree when a limb falls off or the trunk gets damaged. But sometimes, animals or insects dig into the tree and create the hollow themselves. The inside of a tree hollow is usually nice and cozy, like a little bedroom, and animals will sometimes line it with soft materials like leaves or fur to make it even cozier.
Overall, tree hollows are important homes for many animals and help them survive in the wild. So next time you see a hole in a tree, remember that it could be someone's home!