|Image from Wildlife Queensland|
Short-Beaked Echidnas have clawed front feet that are exceptional for digging. These feet also help them to locate their favorite meals - ants and termites - so that they can slurp them up with their long tongues. Short-Beaked Echidnas have no teeth. Their bodies are covered with spines, interspersed with hair. These are used for defense. Short-Beaked Echidnas have compact, muscular bodies, and are able to roll up into a ball that is extremely difficult for predators to penetrate. They have wonderful senses of smell, but poor eyesight. Short-beaked Echidnas are warm blooded, and they do in fact produce milk for their young.
Short-Beaked Echidnas are typically very shy, solitary creatures, and will only come together to mate. After mating, the female will lay a single eggs, which is incubated in a pouch until hatching. The baby (unofficially called a puggle!) will remain in the pouch (similar to marsupials) until it's spines begin to grow. At that point it is raised in an external burrow. Short-Beaked Echidnas are the only Monotremes that are commonly found within captivity. They have also been bred in captivity.
Thanks to @iflylikeicarus for the suggestion!