If you see a tree which has been stripped of its bark, this has most likely been done by ring-tail possums gathering materials to build their nest, which is called a drey. The Stringybark eucalypts are most commonly targeted because of their loose fibrous bark.
During the day family groups retire to spherical nests, about the size of a football, to sleep. The nests are made of leaves, grass, twigs, moss and bark, and tree hollows are also used. When making their nests, the males and females carry building materials with their tails. The possums also have two thumbs on their front feet, which helps them climb. (For more background information – https://reptilepark.com.au/animals/mammals/ringtail-possum/)