Algae growth on their fur causes a greenish tinge during the rainy season. Sloths are uniquely adapted to arboreal life. They are extremely slow, with arms longer than their legs. Their actual digits are closely bound together by tissue covered with skin and hair ending in long, strong, permanently curved claws. The palms of their hands and soles of their feet are leathery and, together with the claws, form efficient hooks that can easily suspend their body from branches.
Sloths defend themselves by biting and lashing out with their arms and formidable claws.
However, their best protection is their slowness and concealing coloration. Unlike most mammals, the sloth's body temperature varies considerably, fluctuating with the temperature of the surroundings. Reportedly, sloths have color vision, but their eyesight is generally not well-developed. However, their senses of hearing and smell are keen. Individual hairs are corrugated, providing surface grooves on which the algae grow.