Where do squirrels sleep at night?

They build nests that they sleep in. Many have nests in trees or in other high places. Yes, some do sleep in the warmth of an attic or barn.

I was going to say that one of them sleeps with me, but you probably wouldn't have bought that as a good answer. :) I believe they have nests in trees, or somewhere high enough up to be safe. I know in the winter, when the leaves are off the trees you can see their summer nests way far up in the boughs. Squirrels nest, birds roost at night.

They make nests out of twigs and leaves,and the inside is lined with fur or feathers,and build it high in the trees with 2 exits in the nest..there nest isnt too high that wind would blow it..and not to close to the ground so predators cant get them..and of course the also have nests in the hollow part of trees that we see in cartoons lol and did u know that if they get flea in the nest they will just up and leave and make a new one somewhere else?And did u know they can swim? they can dog paddle!! lol!!

Most probably on trees , I am not sure.