Dense colonies emerge onto sunlit mudflats at low tide, where males rhythmically wave an oversized, brightly colored major claw to attract mates and signal territorial boundaries. Crabs continuously scrape surface silt with their smaller feeding claws, sorting out microscopic algae and bacteria before depositing clean sediment in small spherical pellets. When incoming tides or predatory birds threaten the flat, they retreat underground and plug their burrow entrances with mud plugs to trap pockets of breathable air.
