A tree hollow is like a small cave inside a tree. It's where squirrels like to live because it's warm and safe. Think of it like a little bedroom for them!
In their cozy home, squirrels keep their food supplies. They like to collect nuts and seeds and store them inside the hollow, just like putting away toys in a toy box!
At night or when they want to rest, squirrels sleep in their tree hollow. It helps them feel safe from rain, wind, and other animals.
So, tree hollows are very important for squirrels to sleep and keep their food safe!