Pigs can breathe through their butts if their heads are underwater.

In addition to being highly intelligent, pigs are also biologically, shall we say, unique. While they can’t breathe underwater like a fish, they can breathe through their butts when their heads are underwater or when in other kinds of distress. 

This was discovered at the height of the COVID-19 pandemic, when researchers were looking for alternatives to mechanical ventilation. Rather than pump oxygen into a patient’s lungs via their windpipe, they wondered, could they deliver it via their intestines instead? The answer, at least in the case of pigs, mice, and rats, is yes.

Scientists took inspiration from aquatic creatures that breathe through their intestines, such as sea cucumbers and catfish, when conducting their experiments. They found that, when in distress, intestinal breathing is indeed possible in our porcine friends — if not exactly ideal. Though they’ve yet to conclude whether a similar approach would be safe and effective for humans (presumably due to a lack of volunteers), their studies nevertheless reveal another way in which pigs are more fascinating than they get credit for.