The western pygmy possum is solitary and nocturnal. During the day, they shelter in tree hollows or other natural crevices, birds' nests, or dense vegetation. At night, they travel in search of food or mates, typically moving around each day, and they may migrate to different areas over the course of a year, depending on local plant resources. They spend most of their time in the trees, using their grasping paws and prehensile tails to grip onto branches, grasp nest materials, and open flowers to access nectar. They have been described as making a rapid chattering noise.