When we think of sloths, the image that comes to mind is one of stillness, patience, and near-silent movement. Yet, hidden in the treetops of Central and South America, sloths have a surprisingly loud and dramatic way of finding love.

Biologists studying the three-toed sloth (Bradypus variegatus) have documented that when a female enters estrus — the period when she is ready to mate — she does not rely on subtlety. Instead, she lets out a high-pitched scream that echoes through the rainforest canopy. This unusual call functions as a signal to males in the area, guiding them through the dense forest toward her.

Unlike many animals that have fixed mating seasons, three-toed sloths can reproduce year-round. The female’s scream is therefore a crucial adaptation, ensuring that males know when she is fertile. Researchers note that males are strongly attracted to these calls and will often compete for the chance to approach the female.

While the image of a “screaming sloth” may sound humorous, the behavior underscores the importance of communication in the animal kingdom. In thick forests where visibility is limited and sloths move at a famously slow pace, vocal signals provide an efficient way to overcome distance and connect potential mates.

This discovery also highlights how much there is still to learn about the secret lives of sloths. Far from being “lazy,” they have evolved unique strategies to survive, reproduce, and thrive in their environment. And next time you imagine a sloth hanging quietly in a tree, remember: sometimes even the quietest animals have the loudest love songs.