 The pouch of the "M. brevicaudata" is not as developed as in other marsupials.The young cling to the mother's fur and nipples and ride on her back when they are old enough to hold on.The shape of the urethral grooves of the males' genitalia is used to distinguish between "Monodelphis brevicaudata", "Monodelphis domestica", and "Monodelphis americana".