The platypus's diet consists of yabbies(various insect larvae), shrimp, crayfish, earth worms, meal worms, May flies, dragonflies, mussels, trout eggs, frog eggs, tadpoles, small frogs and fish.  The platypus searches for its food by diving to the bottom of  streams and rocking its head from side-to-side through the mud.  These dives  last for about 40 seconds.  When forging on the bottom, the platypus swims with its eyes, ears, and nostrils closed.  It uses its electro-sensitive bill to locate and probe for food.  The platypus locates its prey underwater by sensing the electric current created by the prey's muscle movements.  This is why the platypus is such an excellent hunter at night or in murky water. 

      The inner surface of the platypus's stomach is lined with a cornified (horny) epithelium.  There are no glands in this area to produce hydrochloric acid and peptic enzymes which provide the digestion of protein in other mammals.  It has been suggested that the breakdown of food in the stomach is assisted by the grinding action of ingested mud. 
      Normally the platypus eats up to half of its own body weight.  It takes up to twelve hours to collect this amount of food.  In the summer the platypus is likely to eat even more than this and stores the extra fat in its tail. This stored fat is used as a food supply when additional food is needed in the winter or for extra energy during the breeding and incubating season.  Even during the winter when it is cold, the platypus still goes swimming for food.  During the winter period a platypus generally eats 18% fresh water shrimp, 4% caddis fly larvae, 12% fly larvae, 18% May fly larvae, 17 % Horsehair worms, and 1% small snails daily.  In the summer it generally consumes 64% caddis fly larvae, 18% fly larvae, 9% stone-fly larvae, and 9% dragon fly larvae.
      Several animals prey on the platypus.  These include foxes, crocodiles, birds of prey, goannas, carpet pythons, large fish, cats, dogs, and dingos.  Water rats sometimes kill the young platypuses in the nesting burrow.  Also floods sometimes claim the lives of young platypuses.  Other factors that kill platypuses are water pollution, crab pots, and fishing nets. Due to the fact that the platypus is specially adapted to its freshwater environment, the greatest danger to it is the deterioration of its living environment by humans and population growth.