Echidnas are monotremes, a term for egg-laying mammals. The female develops a moon-shaped fold of skin on her abdomen that forms a pocket in which a single egg is deposited and incubated.
Echidnas dig into the earth and cling with their claws and spines or roll into a spiny ball when disturbed. Their snout is very important for sensing the environment. Vision is not their most important sense and they can do relatively well with impaired vision. Echidnas' external ears are actually quite large. However, they are hard to see because of their spines. They have the typical mammal inner ear arrangement (three bones called malleus, incus, and stapes). Their sense of hearing responds best to lower frequencies and may be ideal for hearing sounds made by food items, especially termites and ants.
Status in the Wild
Short-beaked echidnas are a medium-size monotreme mammal, rarely weighing more than 7 kg (15.4 pounds), covered on their back with stout spines among a fur coat of varying color from light brown to black. It is impossible to distinguish male from female echidnas by their appearance without picking them up to determine the presence or absence of a penis. They have a short, stubby tail. The hollow spines that cover most of their body are yellowish at the base and black at the tip and measure about 2 inches long. The underbelly lacks spines but is covered with fur and thick bristles. They have a long, tubular snout. Since they do not have teeth, they use their long, sticky tongue to gather food. There are two sets of hardened, keratinous spines (one set on the roof of the mouth and one at the base of the tongue) for grinding insect exoskeletons into a paste. Their feet have five flat claws that are adapted for digging, though their hindfeet are used primarily for grooming.
They are abundant in their natural habitat.
Listed as “least concern" on the IUCN Red List (International Union for Conservation of Nature and Natural Resources).