Leave it to Majoid crabs to make me feel like a Scrooge. These crusty creatures that live in the Pacific Ocean are really good at decorating, while my wife has to threaten me to decorate for holidays.

Majoid crabs, known as decorator crabs, attach things to their sticky legs to help them hide from eels and other predators that want to eat them. In the ocean, they will attach sponges, algae and other natural items to their legs.

Researchers at the University of Delaware ran some experiments to find out more about the crabs. They dropped craft pom-poms that had been soaked in water into fish tanks. Half of the crabs were given a shelter to see if having somewhere to hide affected how much or how fast the crab decorated.

In the study, all of the crabs were fully decorated within 24 hours. Most of the crabs decorated within six hours of having access to the pom-poms. According to University of Delaware marine scientist Danielle Dixson, this shows that decorating is a way to avoid predators, because they do it so fast.

Other decorator crab species decorate their body first, probably to protect their vital orans. But the ones they were studying, known scientifically as Camposcia retusa, decorated their arms and legs first when they had a place to hide. This made sense because when Camposcia retusa hides, a little bit of their arms were sticking out of their hiding spot. When there was no place to hide the crabs decorated everywhere.

You may think that more decoration would be best, helping the crabs completely hide. But carrying around a bunch of ornaments takes more energy and they would also be slower if they tried to escape.

— Brett French, french@billingsgazette.com