The pygmy possums are a family of small possums that together form the marsupial family Burramyidae. Pygmy possums range in length from about 2 to 5 inches, and usually weigh between 10 and 50 grams (0.35 and 1.76 oz). They are nocturnal and omnivorous, living on a diet of invertebrates, fruit, seed, nectar and pollen. They are excellent climbers, due in part to their prehensile tails. The five extant species of pygmy possum are grouped into two genera. Four of the species are endemic to Australia, with one species also co-occurring in Papua New Guinea and Indonesia.