TLDR? "All six species of sloths live in tropical forests. It’s a hot and humid environment that means some of the normal advantages of an endothermic system a

TLDR? "All six species of sloths live in tropical forests. It’s a hot and humid environment that means some of the normal advantages of an endothermic system aren’t really required – the environment’s already warm, so you don’t have to expend an enormous amount of energy to keep your muscles and cardiovascular system warm. So sloths don’t."