General Science

5 Weird Facts About Sloths

posted: 10/20/16
by: Mary Beth McAndrews
Amber Goechoel

It's International Sloth Day, also known as the best day of the year. It's the day to celebrate the slowest, laziest creatures in the animal kingdom. While looking at photos of their adorable snouts is enough cause for celebration, there's a very scientific and strange side to these two- or three-toed mammals. Here are a few weird facts that you may not know about sloths!

  • Sloths only poop and urinate once a week and it's always in the same place. Yup, that's right, sloths only do their business once a week. They leave their comfy place in the trees to go to the bathroom at the base of the same tree. Leaving their place camouflaged in the rainforest's canopy leaves them vulnerable to predators. Since sloths don't move very fast, their defense is usually scratching, biting, and shrieking. Take note that it is usually only three-toed sloths that do this; two-toed sloths will usually do their business from the canopy!


  • A species of moth is completely dependent on sloths. This may explain the sloth's habit of leaving trees to poop! The pyralid moth is only found in the hair of sloths and their life cycle depends on them. When the sloth descends to poop at the base of its favorite tree, pregnant moths will leave the sloth to lay eggs in the sloth's poop. From there, the larvae grow, hatch, then fly to find a sloth, a.k.a. a moth mating ground.
  • There is a specific type of algae only found growing on sloths. Sloths appear green in color because of the algae that grows in their thick hair. But did you know that this algae, Trichophilus welckeri, is only found on sloths and exists solely for this symbiotic relationship? It is hypothesized that there may be cracks and grooves in sloth hair that can hold water, which creates the perfect environment for algae and other microorganisms. You can read more in the BMC Evolutionary Biology


  • Sloth bodies are only 25% muscle. While they must have limbs of steel from all that hanging and climbing, sloths' limbs are rendered pretty useless on land. Their hind legs can't provide any support or power on the ground, so they must drag themselves along. This lack of muscle mass also means they can't shiver if it gets too cold.
  • Sloths have extremely low body temperatures. Sloths have the lowest and more variable body temperature of any mammal, according to the San Diego Zoo. Their temperatures can range from 74 to 92 degrees Fahrenheit!
About the blog:
Welcome to the inSCIder, where you can connect with the people who bring Science Channel to life. Find out what's in the works here at SCIENCE, share your feedback with the team and see what's getting our attention online and in the news.
More on