We all know the sound a happy cat makes. But did you realise a bunch of other animals also purr, including big arse polar bears? Neither did I.
A purr is a tonal fluttering sound produced by an animal's vocal folds or muscles in the larynx. They are essentially air vibrations caused by a deliberate way of breathing. In adult mammals, this vocalisation is usually made to express contentment or to convey they do not pose a threat.
While purring sounds are most commonly associated with species of feline, they are made by a surprisingly large number of other animals including foxes, hyaenas, rabbits, squirrels, guinea pigs, gorillas and bears. That's right - when suitably pleased, one of nature's most fearsome apex predators purrs just like a lickle pussy cat.
Here's the skinny from the North American Bear Center:
Black bear cubs make motor-like pleasure sounds as they nurse. Similar to a cat's purring, bears make this pleasure sound when they are especially comfortable, nursing, or eating a special treat. Adults make this sound with a deeper voice.
You can hear an audio recording from the same website here.
The sound has been observed in many bear species including polar bears. Here are a couple of examples caught on video:
So there you have it. Despite having the ability to disembowel you and eat your face off in the blink of an eye, bears are just big ol' cuties at heart. Probably.
Today I Discovered is a daily dose of facts for Lifehacker readers - the weird, wonderful and sometimes worrying. Most of the time, it's just mind-blowing. Let us know if you discovered anything that blew your mind in the comments!