A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The Pistol Shrimp can snap its claws together to create a sound of 218 decibels, louder than as supersonic jet at full speed. It only lasts for 1 millisecond. The snapping action also creates a bubble that is greater than 5000 Kelvin, close to the surface temperature of the sun.
21
Squirrels forget where they hide about half of their nuts.
698
Sharks have been on the planet longer than trees.
14