springtails

Here is a group of tiny springtails (+/- 2 mm) floating on the surface of a puddle. They are arthropods but not insects. Springtails are amazing in a lot of ways, including their sheer numbers. But one of the coolest things about them is their skin, which repels water and other liquids. That’s important because, unlike insects, they breathe through their skin. So if it gets wet or gunky, they’ll suffocate. Click through to the references for an excellent article about how their skin works.