Echidnas are a part of the rare group of animals called monotremes: they are mammals that lay eggs. (ID 86500329 © Paul Looyen | Dreamstime.com)
If you're an animal that lives in a hot climate, there is one life skill that sits at the top of your survival list.
Staying cool.
Animals use different strategies to accomplish this goal. Many desert reptiles hide during the day, staying active during the cool night. Many mammals pant to release body heat through their mouths. Kangaroos stay still during the hottest hours and lick their wrists to cool the blood vessels found there. Whatever works!
But few creatures cool off like the echidna. This spiny marsupial uses a technique that is as weird as it is effective.
It blows bubbles of snot!
Booger bubbles
Okay, we know the question that you all have for us. How does spraying mucus all over itself help the echidna cool off?
The principle is the same as panting, or the 'roo licking its wrists, or humans when we sweat. When moisture evaporates off of an animal's body on a hot day, it cools the blood near that area. That cooler blood then circulates through the rest of the body, cooling the animal down.
So while the echidna's method is a bit unusual, it relies on a classic principle.
As it blows snot bubbles out of its nose, they pop and spray moisture across its tiny nose. The moisture evaporates, the blood there cools, and the echidna survives another extremely hot Australian day!
Don't try using it as an excuse, kids
This infrared image shows how much cooler the nose of the echidna is compared to the rest of its body. (Christine Cooper)
We know this fact thanks to the work of researchers at Curtin University in Perth, Australia. Their studies featured the short-beaked echidna. The researchers observed the animals under infrared thermography, which helps them see the animal's body temperature. In these images, cooler areas read darker, and you can clearly see how much darker the nose is than the rest of the animal.
Though they have not directly observed this booger blowing behaviour in other species of echidna yet, it is likely that they use a similar method.
As for humans, we do not recommend this as a way to cool down on a hot day. Not only do we already sweat to take care of that problem, blowing snot all over yourself is pretty unhygienic! And kind of gross.
Let's leave the snot bubbles to our animal friends!
