The musk rat-kangaroo is a unique member of its family in two ways: first, it has a well-formed first digit, or thumb, on each hind foot, and second, it is the only kangaroo regularly to give birth to twins. It is also unusual in other respects; for example, it often moves around on four legs in the manner of a rabbit. Both male and female produce a pungent musky odor, but the reason for this is not known. Their diet includes a wide range of pant matter, from palm berries to root tubers, and they also eat insects and earthworms. Little is known of the social habits of the musk rat-kangaroos, but they seem to move singly or in pairs. The young re usually born in the rainy season (February to May), but this can vary.