Sifrhippus was a species of horse about the size of an average duck and roamed North America 56 million years ago.
2
Rattlesnake mating sessions have been known to last more than 22 hours.
232
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Travis was a chimpanzee who socialized with humans since birth. He could log onto a computer to look at pictures, watch TV using a remote control, brush his teeth, feed hay to his owner's horses, water plants, and learned the schedule of passing ice cream trucks.
11
The difference between antlers and horns is that antlers are shed each year and are made of bone while horns are kept for life and are made of living tissue and bone with a sheath that is very similar to human finger nails.
10
Crows living in some urban areas drop nuts into traffic to let the passing cars crush them, then they wait for the red lights to stop the traffic so they can grab and eat it.
17