It looks like a squirrels nest.
Squirrels usually reside in the trees and rarely nest on the ground but chipmunks often times burrow and nest in holes in the ground rather than holes in the trees. Chipmunks like to live in the insulation of the walls of your house if there is easy access into a wall near or below ground level as well.
it looked like a hole in the ground and leves on in
I say that a squirrels nest is smaller because a squirrels nest is up in a tree. A rats nest is bigger because they usally live underground which is bigger than a tree.
No they cant share a nest or tree they will fight over acorns and peanuts and other nuts!
Like many animal nests (except insect's) a squirrel nest is called a drey.
A squirrel's nest is called a drey.
A squirrel's nest is called a drey
This is a link to a page showing leaves, and a squirrel nest made of oak leaves. Pretty much looks like a large clump of leaves in the top of a tree. http://grandpacliff.com/Trees/AutLeaves.htm
Unless they're a California Ground Squirrel or another type of squirrel that lives in the ground, then yes. Most squirrels live and make their nest in trees.
The mother squirrels will usually look for food close to their nest so she can "watch" the pups.
pretty warm
Their nest