Except when breeding, brush-tailed possums tend to lead a solitary life. They stick to their 'home range', which they mark out by coating tree branches with a scent released from glands on their chests. If two possums meet at night they try to avoid each other - fights between adult possums are rare, although they may make threatening noises towards each other. Young possums may be attacked if they try to take over an adult's range.
In the bush, brush-tailed possums feed on leaves, buds, flowers and fruits. They have strong teeth and often use their front paws to hold their food while eating.
Brush-tailed possums are marsupials, and their young are usually born in May and June after a gestation period of 17 days (humans have a gestation period of nine months). The newborn possum finds its way to the mother's pouch and attaches itself to a teat.
After feeding and growing for about five months in the pouch, the young possum spends another two months clinging to its mother's back as she moves about. Usually only one young is born at a time, and males do not take part in looking after the young.
By the time they are seven months old, the young possums are independent of their mothers. They are fully grown by about 10 months, and the females will usually start to breed for the first time when they reach 12 months of age.