The photos were shared on Reddit by user VanillaBean5813, who explained, "Our sea urchins like to cover their heads so we 3d printed them some hats." They went on to share the original hat prototype, a pointy witch hat. But how do they pick up the hats to put them on their heads? Well, they have tube feet that they can grasp objects with.
Bored Panda was able to interview Reddit user VanillaBean5813, who explained that making hats for sea urchins is a family endeavor: "My dad is the real aquarist (and also a redditor), I modify 3D models from the internet, and my mom runs the 3D printer." Bored Panda goes on to provide more information:
The redditor explained that the project started when the family got their first baby corals and the "sea urchins started carrying them away, which is damaging to them."
After the initial hat designs, they had several improvements. "We went through a few iterations of hats—we learned that hollow structures were too floaty and that caused them to lose the witches hat we made."
u/VanillaBean5813 said that it's not entirely clear why sea urchins like to cover their heads. "We think it's either a defense mechanism for their vulnerable backsides or protection from tank lights."
VanillaBean5813 is probably right about why their sea urchins cover their heads. In this video created by Dr. Klaus Stiefel, you can see the sea urchins in action, covering themselves with various objects. He explains that they do so for many reasons, including to camouflage their bodies from predators and to protect themselves from UV radiation. Go check out some of the images in the Bored Panda article – the sea urchins are looking quite dapper in all of their fancy hats!
