Mudflats form when silt and mud are brought in by seas, oceans, and tributaries. The mud and the silt are deposited into bays and lagoons when the tide comes in. The water mixes with the mud and silt, creating the muddy quicksand that occurs in mudflats. Once the tide lowers, the mudflats are exposed along with what inhabits them. This habitat has the distinct smell of rotten eggs but it is packed with invertebrates and bacteria. Even though mudflats have little vegetation they are home to marine life like mollusks, crustaceans and worms such as lugworms, oysters, cockles and snails. This habitat is also a very important breeding ground for many species of fish.