That Ball of Leaves In Your Michigan Tree Isn’t A Bird Nest

One of the best parts of living in Michigan is that we experience all four seasons. Trees bloom in spring, summer comes, everything is green and lush, and then fall appears. All the green turns brown and ends up on the ground, except for those balls of leaves in the trees. Working for the county parks for several years has caused me to see these all the time and think nothing of it.

I have always been under the assumption that those are just leaves that have fallen perfectly and gotten caught in the tree. Not only am I technically wrong, but those balls have a name. 

More Than Just Random Leaves

The balls in question are called dreys and can be found year-round. We just don't typically see them until there are no leaves to hide them away. These dreys serve an important function: a squirrel's home. Much like a bird's nest, these dreys are made up of sticks, dry leaves, moss, and sometimes fur woven together to make a hollow home for the squirrels.

How Do Squrriels Nest

According to BBC Earth, the mothers make the nest over several days, usually making one to two exits for the squirrels to go in and out of. Since squirrels don't hibernate, they need to make a place where they can get out of the cold and store their food to survive the winter and escape the heat in the summer.

So next time you see a drey in a tree, don't try knocking it out of the tree. There could be a squirrel inside!