Platypuses are carnivorous, which means they eat meat but not plants. They hunt for their food in the water where they live. As they swim, they try to detect food along the muddy bottom of the river, stream, pond or lake using their sensitive bills. When platypuses find something interesting, like shellfish, insects, larvae or worms, they scoop it up in their bills, store it in their cheek pouches and swim to the surface. Since they only have grinding plates and no teeth, platypuses use any gravel or dirt they scooped up while on the bottom of the waterbed to mash their food into digestible pieces.