Howler monkeys live almost entirely in the rain forest canopy. Leaves are the main part of their diet, so they have everything they need high in the sky. Since it’s hard to see through the greenery in the canopy, animals that live there make a lot of noise to communicate. In fact, howler monkeys are thought to be the loudest animals on land. Their bloodcurdling roars can be heard for three miles. (Micha Klootwijk/ Shutterstock) Read More