Judy, can I please make a correction? The antechinus is not a rodent, it is a marsupial. It is in the Dasyuridae family, which includes about 70 species of carnivore/insectivore, ranging in size from tiny dunnarts to cat-sized quolls to the Tasmanian Devil. Rodents, such as mice, rats, squirrels, all the way up to the capybara, are placental mammals. [The third group of mammals is the monotremes, the platypus and echidna]. Placentals and marsupials are fundamentally different in many ways. Many people think that all marsupials have pouches, but not all do. Many species, including the 15 antechinus species, have very small rudimentary folds rather than a pouch.