Bladderworts using suction traps catch their prey. Their leaves have a number of small bladders. A tiny animal is sucked in and dies that comes too close to bladders. Most bladderworts that drift near the surface of ponds and lakes are water plants. Above the surface are only the flower spikes. Each bladder, with a trapdoor surrounded by bristles at one end is flask-shaped. It looks like a small crustacean. Water flea Daphnia, which may be in search of protection, is attracted. Creating a partial vacuum inside the trap is ready to work when water is pumped out. The door flies open when an animal touches a trigger hair, and water rushes in, carrying the animal with it. Star-shaped glands inside the bladder absorb its remains.