A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The Basenji dog is the only dog that is not able to bark.
4
Cats and dogs can hear ultrasound.
350
Christmas Island has bridges for crabs to stop them getting run over during the mass migration.
9
When the "Elephant Whisperer" Lawrence Anthony died, a whole herd of elephants arrived at his house to mourn him.
25
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