[Jessi yawns]   Sorry, guys! Do you ever have those days where you just don’t have the energy to do all that much? And when you do move, you move really slowly?   Well, that’s pretty much what every day is like for a sloth.    Sloths are the slowest mammals on Earth.    Just how slow are they? Well it can take a sloth up to an entire month to travel a single mile on the ground.    But that’s OK, because sloths spend most of their lives in trees, where they can move just a little bit faster.    Their powerful arms and curved claws let them move easily from branch to branch in the rain forests of Central and South America, where they’re from.    Sloths are identified by the number of these claws that they have on their front feet. There are two-toed sloths and three-toed sloths.   But good luck actually spotting a sloth swinging through the trees -- these guys spend very little time moving, and a whole lot of time sleeping and eating.   Sounds sort of boring, doesn’t it?   Wrong!   If you ask me, sloths are super cool.    They’re not lazy -- they’re just really good at conserving, or saving, their energy.    Their diet of leaves and bark doesn’t provide them with a whole lot of nutrition, so they need to save as much energy as they can.   One way sloths manage to conserve their energy is by keeping their food in their bodies for as long as possible.   Sloths have big stomachs that can hold a large amount of food. While it might take you or I just a few hours to digest our breakfast, it can take a sloth 30 days to digest a single leaf.    Since they digest their food so slowly, sloths don’t get a lot of energy very quickly from their food, but they also don’t use a lot of energy to break it down.    Plus, because their stomachs work so slowly, they don’t need to go to the bathroom as often as we do.   In fact, one of the few times that three-toed sloths come down from the trees is for their weekly potty break.    Once a week! That’s it!   Another weird way sloths conserve energy is by having a naturally low body temperature.    If our body temperature changes more than three degrees, it probably means that we’re sick.    But that’s not so for the two-toed sloth. It has the lowest body temperature of any mammal in the world -- it can dip as low as 30 degrees Celsius.    Most mammals, including us, have body temperatures of 36 degrees Celsius or higher.   After all, it takes a lot of energy to keep your body warm. So when sloths aren’t active, which is most of time, their bodies just automatically switch into low-energy mode, and their body temperature drops.   The last weird way that sloths save energy is my personal favorite.   Three-toed sloths are the only mammal that can rotate their heads almost all the way around their bodies, like owls do.    This is because they have more vertebrae, or bones in their neck, than other mammals do.   This cool trick helps them look for food and keep an eye out for predators without having to go anywhere or do anything.   They can just hang out, and twist their heads around, observing the world around them.   So sure, sloths are slow -- but not because they’re lazy. They’ve just adapted to a nice, mellow, low-energy lifestyle that works out well for them.    They’re basically the ultimate energy-saving machine!    Thanks for joining us on SciShow Kids! I'm Jessi; this is Squeaks, and we'll see you next time.