A group of pugs is called a grumble.
10
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Parrotfish make themselves a kind of mucus 'sleeping bag' which masks their smell from predators and keeps parasites away.
4
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Dolphins have names for one another.
18