The sloth eats mostly leaves and fruit, making it a heterotroph as it does not produce its own energy. Sloths also occasionally eat the bugs and beetles residing in the algae that grows in their fur. Because the leaves they eat are hard to digest and provide little energy, sloths have very large and slow-acting stomachs (it can take days to digest a meal, and food may remain in the stomach for a week or more), and tend to not spend a lot of energy. As a matter of fact, sloths only comes down from its usual position upside-down in a tree about once a week, or longer, to rid themselves of excrement. The sloth's main source of water is the water within and running down leaves.