my daughter's maybe favorite animal

every morning i watch these two squirrels. always running around, up and down the stairs, up the telephone pole, all while their tails are flicking incessantly. i thought that, by nature of squirrels in general, they are just hunting for food. but it really looks as if they are playing (chasing each other around, etc.). can this be? do squirrels play? and is it safe to assume that these are the same two squirrels each day?