Dotilla myctiroides

Dotilla myctiroides is a species of sand bubbler crab found on sea coasts in tropical Asia and East Asia, from Karachi to Japan. They breed throughout the year but activity peaks during the monsoons. This species builds a burrow, called an "igloo", in unstable sand as well as in well-drained and firm sand. In building the igloo, the crab excavates sand and forms it into spherical pellets. These pellets are used to form a circular wall and roof in the burrow. The resulting structure holds a small amount of air in addition to the crab itself.