Coots are water birds that belong to the Rallidae family. These birds are commonly found in marshes, swamps, and lakes. Apart from coots, there are several other synonyms for this bird, including mud hen, water hen, marsh hen, moor hen, and swamp hen. Mud hen and water hen are perhaps the most commonly used synonyms for coots in North America. Marsh hen and swamp hen, on the other hand, are more commonly used in Europe. Moor hen is used specifically for the Eurasian species of coots. These synonyms are used interchangeably by birdwatchers, researchers, and environmentalists who are interested in the behavior, ecology, and conservation of these fascinating birds.