Babies Often Smile in Their Sleep From the Start If you ... In other words, a 2-week-old's sleepy, ear-to-ear grin is very cute, but it's not an emotional response to parents or other caregivers.

And if some might argue that human babies are more adorable ... and spread a smile on their faces too! If you know other cute little animals, let us know in the comments! We do our best to ...