 Hello, and welcome back to ACMI Fun Facts. This time around, we've got some fast facts about one of nature's slowest creatures, the sloth. There are two types of sloths. Two-toed and three-toed spread across six species. Their slow speed is due to their low metabolism, which allows them to digest their plant-based diet over a period of a few days. Moving slow is still very tiring for little guys, which is why they sleep as much as 15 hours a day. Despite their slow movement on land, sloths are talented swimmers with their slowed metabolism, allowing them to hold their breath for around 40 minutes, thanks to a slow heartbeat. Sloths haven't always been so small. In fact, in prehistoric times, they were gigantic creatures called megatherium. Megatherium got to be as big as 22 feet tall and weighed as much as 7 tons. The craziest part is that they may have been alive as recently as 11,000 years ago. A smaller version existed called Megalons, which measured 8 to 10 feet and weighed a maximum of 800 pounds. What's truly interesting is that the name for these creatures was proposed by Thomas Jefferson, based on fossils found in West Virginia. That's all for today, but keep your eyes peeled for another episode of ACMI Fun Facts.