Show Off Your Smarts!

Remember Will's old "Show Off Your Smarts!" feature? He'd throw out a topic and turn the microphone over to our brilliant readers. Sounds to me like a great way to kill time on a Friday. Let's revive "Show Off Your Smarts" and talk about amazing animal facts. I'll throw out a few:
- A crocodile can digest a steel nail without chewing.
- Sand tiger sharks attack each other in their mother's womb.
- An octopus has three hearts.
- Bees and dogs can smell fear.*
*I'm taking the kid in Jerry Maguire at his word here. Probably should have fact-checked. Your turn.