Squirrel baby

I'm squirrel-sitting for a friend who rescued this tiny little creature from her front porch about a week ago. He eats puppy formula every three hours out of an eye dropper which he's learned to nurse from. Then he nestles back in to his little box nest (complete with heating pad) and curls up to sleep. Occasionally he jumps and makes cute little sounds in his sleep - what is he dreaming about? Does he remember his nest and his mama? The outdoors at all?