Mary

Marsupials are awesome. I remember reading how joeys (or whatever they're called when they first emerge) are responsible for climbing to the pouch and getting settled after they are "born" - how cool is that! And mothers' bodies can slow or abort joey development, based on her current nutrition level (or something like that). Don't know if it's any sort of conscious control, or just the body's natural response to lean times, but it's pretty sensible. I really shouldn't be spouting off "facts" I barely remember without doing some research and providing citations - but oh well.

Of course, it might get sort of annoying having your child climb into a pocket in your stomach for a few years...