The male nightingale has one of the most complex and sophisticated verbal sounds in the entire animal kingdom
Wolves are apex predators that travel in packs and are essential for the health of most ecosystems
They have zygodactyl feet, with the first and fourth toes facing backward, the second and third facing forward, so they can grip tree trunks more efficiently
Gerbils were named after jerboas, which are also rodents. Jerboas look like gerbils but are not closely related to them.