Black-tailed tree rat (Thallomys nigricauda) sunning, also known as basking, at sunset. Sunning or sun basking is a thermoregulatory or comfort behaviour used by animals. This clip was filmed in the dry winter season where temperatures drop significantly at night. This species of rodent is a member of the mouse family Muridae. The Black-tailed tree rat is an arboreal rodent which is found in Angola, Botswana, Namibia, South Africa, and Zambia. They are nocturnal and emerge from the nest to forage shortly before darkness sets in. Foraging is usually preceded by a period of sunning and grooming. Photographed in Okaukeujo restcamp, Etosha national park, Namibia, Southern Africa.