Ridiculous hats aren’t exclusive to British nobility—sponge crabs also make bold fashion statements with their headgear.

And now, new research unveils for the first time how these crustaceans form such exquisite crowns.

The 130 or so species of sponge crabs in the family Dromiidae are so named because they sport oversize “hats” made of living sponges. The animals cut themselves a chunk of sponge and shape it to fit, then carry it on their backs using special spines on their rear limbs.

Presumably, this behavior repels predators: Sponges aren’t exactly appetizing, and often contain potent poisons. (It’s unclear if the sponges benefit from being carried around, but they don’t appear to be harmed by becoming hats.)

So the fact that they