Way more adorable possum relatives than the United States has.
These Cuscuses are from New Guinea (top) and the Indonesian islands (bottom). Neither of them are very well-studied, and neither is very accessible to study, either. They live in dense rainforests and are strictly nocturnal. What is known is that they’re typically found in pairs, but other than that are not group-oriented.
Proceedings of the Scientific Meetings of the Zoological Society of London for the Year 1858.