They eat smaller microorganisms by engulfing them. There are nearly 2,000 species of rotifers which differ in their appearance and lifestyles. Some swim, some crawl, some stick onto surfaces using a sort of glue but they all are multi-celled tiny animals with cilia which they use for locomotion and food retrieval. Some eat plants, some algae, some other small animals but all are important foods for larger animals. A few species can survive their water being completely dried out.
Water bears have a head and four pairs of legs with claws.
They are also called Tardigrades or moss piglets and their scientific name is Hysibius . They live among plants which they eat. A total of 40 some species live in North America. When the water they are in dries up, so do they. When wet again, they come back to life.