Apart from newborn squeaks, some sloth species could generate low hisses as a defense mechanism when they feel attacked. Although they avoid confrontation wherever they can, their defensive hissing might deter smaller predators or alert other animals of likely threat. Though they are generally silent, adult sloths hide from predators more by scent marking and little movement than by sporadic sounds. Their slow style of life suits this propensity to reduce noise since vocalizing would attract attention and render them more susceptible.

Amazingly, the silence of adult sloths contrasts with the more boisterous activity observed in other jungle creatures, such as monkeys or birds, who often employ vocalizations. Sloths prefer silence since loud noises in the rainforest could attract unwelcome attention very quickly, so helping them to save energy and avoid predators.

Research on sloth communication is still under progress with an eye toward how vocalization and scent marking help sloths keep ties with their young and proclaim their presence to other sloths. More understanding of these odd animals will enable one to emphasize how sloths have changed their techniques of communication to suit their environments and energy-efficient existence.