Breathe deep. “In through the nose and out through the mouth” is a common refrain during many a yoga class or relaxation session. But not all animals follow that pattern, or even use those organs to breathe.

There are some turtles that take their breaths through their other end. Yes, that’s right, not through their mouth, but through their anus.

The kids in your life will love this fun fact. You may want to take a deep breath before telling them, and then use their interest as a teachable moment.

Some turtles, including our local painted turtle, can breathe through their butts. “Butt breathing,” also called anal respiration, is not a year-round activity for these species, but a seasonal one. 

This time of year many turtles have become inactive. They have found their way to the bottom of the ponds and have buried themselves under the muck, where they will wait out winter. Though we are all familiar with the process of hibernation, in the case of turtles and other reptiles, the proper term for the off-season resting period is brumation.

Brumation is a seasonal period of dormancy for cold-blooded animals. During brumation, reptiles become less active and their metabolic processes slow. Growth also ceases. Day length triggers brumation, and animals will feed heavily ahead of this resting period to build up reserves. There are, however, a few differences between hibernation and brumation.

You can call this the tale of The Turtle and The Bear. The term hibernation, as already noted, is used most often to refer to mammals, while brumation refers to cold-blooded beasts. During hibernation, animals cease both feeding and drinking water, though during brumation water is still needed. Hibernation is a true prolonged sleep, while brumation can be punctuated by activity. Prior to hibernation, animals will build up fat to use for energy. In addition to this, before brumation, reptiles will build up glycogen that they can use for energy to power their muscles during those periods of activity.

And then there is that breathing problem. As most of us know, turtles usually breathe through their lungs. This is not their only method of respiration. They can also absorb oxygen through their mouth or throat, and — making them the butt of the kids’ jokes — through their cloaca, a posterior orifice that serves digestive, reproductive, urinary and, in this case, even respiratory purposes.

While this method may (or may not) be a pain in the butt, it is an efficient and effective way to respire.

Turtles are not the only animals to use their bottoms for breathing. Some aquatic beetles attach an air bubble to their posteriors and use the captured oxygen in the bubble for respiration during their underwater dives.

Another example of using the butt instead of the brain comes from mosquito larvae. They have a breathing tube or siphon that extends from their posterior end that could be compared to a snorkel. They point their head down and their bottoms up toward the surface of the water where the siphon will break the surface and allow respiration — and possibly provide a smaller target for hungry predators.

No matter which method you find most amazing, all of these anal adaptations obviously kick butt when it comes to helping kids and adults both laugh and learn.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature.