To protect themselves from predators, anemones often contract their hydraulic body into a cavernous den and extend the stinging tentacles toward the entrance. The high sediment dynamics of the region, however,  result in a permanent risk of animal shelters to be obstructed by sand.  By both analyzing field data and conducting laboratory experiments with artificial shelters, the present study explored the den cleaning behavior widely extended amongst alpheid shrimp, and its role in the alpheid-anemone symbiotic interaction.