Scientists and tidepool visitors have known for decades that sea urchins like to cover themselves up. They have tube feet in addition to their spines and each one ends in a suction cup. They pick up objects like shells and algae and hold onto them. Once 3D printing came along, people started making sea urchin hats and, sure enough, the urchins pick them up and wear them. YouTube channel SciShow shared some fun photos but also delves into how this benefits sea urchins in the video below.
Before we look at the science, let’s look at the adorable photos. Thankfully, there’s a Bored Panda thread that includes top hats, cowboy hats (both the 10 gallon and Clint Eastwood styles), and even Viking horns. Since then, it seems that the good folks at Disney’s EPCOT joined the fun. The sea urchins in their tanks now don their own small Mickey ears. Sea urchins with hats have also made it into the video game Stardew Valley.
Ok, now for why sea urchins cover themselves and can thus be tricked into wearing little hats for our amusement. SciShow explains that scientists are still researching this and it may be that different species use the same behavior for different reasons. For example, urchins that live in tumultuous tidepools may be trying to weigh themselves down so they don’t get crashed about in the waves. Other species are using it as camouflage to hide from predators. And still others may just be carrying around extra food.
Melissa is Nerdist’s science & technology staff writer. She did a science project about urchin coverings as a teenager, but never thought to offer them hats. Melissa also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.