Desert crabs are shaken in their shells to protect themselves from competitors who have projects in their homes, scientists have found.
Dartmouth College researchers in New Hampshire tried to investigate the role of vibration when they noticed that crabs living in the earth were maneuvering when others were climbing on their backs. is so intense among Pacific crabs that the animals have no trouble getting on to those who pass by to decide if they can pull out their current owner. Most only move up the ladder of the property when another cancer dies or is expelled.
"They are constantly looking at who is weak enough to be able to get them out and move to that shell," says Mark Liedre, who studies the social life of hermit crayfish. "When someone jumps on them, they get inside their shell and carry this maneuvering movement to deter them." that by shaking their shells the crabs signal that someone is at home and intends to stay in jail. Inside the casing there was a device that mimicked the vibrations produced by small or big crabs.
From the point of view of the umbrella a few meters away, the scientists watched as the hermit crabs approached the shell, offering a spacious open-plan living room. a short walk from the sea. When a new tenant, who hoped, touched the shell, they pushed a button that accidentally chose whether the shell vibrated loudly, weakly or at all.
"When they feel the strong vibration, they immediately withdraw. But when it's weak, it's much more likely to try to overturn the shell, which is the first step in the escalation of the conflict, because that's the only way they can get into the door, "Liedre said. "If there are no vibrations, they hold it for a long time, but the cables do not allow them to roll the shell."
Writing in letters on biology, scientists explain that vibrations are a neglected aspect of communicating with animals. Then they hope to investigate the unusual sound that the hermit's cancer does when eviction is done.