Water proof fur helps insulate against cold temperatures. Platypus use a large, flat, wide bill to capture benthic invertebrates such as crustacean and insects for food. Male platypus are able to produce and deliver venom through a horny spur on the back of the ankle. The venom is produced in a gland behind the knee on the upper thigh. Echidnas have the spur structures but venom is not produced.
Echidnas have a long cylindrical snout used for scavenging forest litter.
A good sense of smell is used to find ants, termites, worms and other insects. Long-nose echidnas compose most of their diet of earthworms. Short-nose echidnas forge mostly on ants and termites. A long tongue is used to capture prey. Excellent hearing is used to locate potential predators.