Platypuses are carnivores. They are predators; they eat small water animals such as aquatic insect larvae of caddisflies, mayflies and two-winged flies, fresh water shrimp, annelid worms, yabbies and crayfish. During summer, they eat more than during winter, in order to build up reserves of fat.
To catch their prey, platypuses must make several hundred dives a day in order to catch enough food. They use the fine, sensitive electroreceptors on their bills, which detect the tiny electrical impulses made by underwater creatures. After locating their prey, they dig up the mud with their bill to grasp them, crushing the creatures between grinding plates in their bills.
Baby platypuses drink mother's milk.
It should be noted that platypuses do not generally eat frogs, tadpoles, fish or plants. Analysis of platypus pellets has - rarely - indicated the presence of fish or frog parts, but on the whole, platypuses do not feed on these creatures.