It's Not The Fleas' Knees

Apparently, there has been a debate raging within insectology circles for 44 years as to whether fleas jump with their feet or their knees. It’s their feet, it turns out. (Or, “tarsi,” as opposed to the “trochantera” knee joints). I’m glad that’s solved. And it was also interesting to learn about resilin, the super-springy protein fleas have that allows them to leap distances more than 200 times their own body-length. But most of all, I just think it’s incredible to watch them do their thing in hi-tech, high-speed, close-up video.