When did the mammals get confusing? Who can't look at a baby and a puppy and see the differences? You can't leave babies at home alone with a chew toy when you go to the movies. Babies will not shimmy under the covers to sleep on your feet when you're cold. Babies, for all their many unarguable charms, will not run with you in the park, or wait by the door for your return, and, as far as I can tell, they know absolutely nothing of unconditional love.