Koalas require a lot of sleep because their food gives them very little energy and eucalyptus requires a lot of energy to digest. Basically most of their energy is spent on digesting the eucalyptus they eat.

You may also like...

Koalas require a lot of sleep because their food gives them very little energy and eucalyptus requires a lot of energy to digest

Flamingos are born gray with fluffy down feathers

Grizzlies will fight for mating rights or to establish their dominance

Squirrels will steal nuts from other squirrels

Starfish are carnivores and eat critters like clams, oysters, and mussels. And clams can flee predators. 

Gentoo penguins propose to their mates by presenting them with the smoothest pebble they can find. If the female accepts, they use it to build their nest together and will mate for life.

Gentoo penguins propose to their mates by presenting them with the smoothest pebble they can find—they use it to build their nest together and will mate for life