An adult koala eats a eucalyptus leaf. Joeys can't break down the toxic, fibrous plants on their own yet. Photograph By David Marks/National Geographic When it’s time to feed the kids, koala moms do ...

Sometimes, dogs do strange things. Beyond rolling in mud puddles or biting themselves, your pet might drink from toilets or lick its butt. In other cases, it may eat its own poop or, worse, the poop ...