Opossums do not sleep at night; they are strictly nocturnal creatures. The Virginia Opossum, which is the only marsupial found in North America, is the species most commonly encountered. Their unique adaptations and habits have allowed them to thrive in diverse environments. This active period, spanning from dusk until dawn, is when they forage and move under the cover of darkness.
The Possum’s Nocturnal Schedule
Opossums are biologically programmed to be most active during the night, typically beginning movements shortly after sunset and retreating to a safe space before sunrise. This schedule is dictated by physiological adaptations designed for low-light conditions. The opossum’s eyes possess a high ratio of rods to cones, making them highly efficient at gathering light but limiting their ability to perceive color.
Their reliance on the night is also a predator avoidance strategy, as they are slow-moving and vulnerable to larger, daytime hunters. Opossums utilize their acute hearing and sensitive facial whiskers, known as vibrissae, to navigate their surroundings effectively in the dark. While their activity is almost exclusively confined to the hours between dusk and dawn, they may occasionally be seen moving during twilight periods, especially when food resources are scarce. This nighttime activity is significantly reduced during periods of extreme cold, as opossums den up for several days to conserve energy and body heat.
Where Possums Rest During the Day
Once the sun rises, opossums seek out temporary, secure locations to rest, as they do not construct permanent dens or nests. They are highly opportunistic in their choice of shelter, utilizing whatever is immediately available and offers protection from predators and the elements. Common daytime resting spots include abandoned burrows dug by other animals, hollow logs, rock crevices, thick brush piles, and tree cavities.
In human-altered landscapes, they frequently take advantage of structures like sheds, garages, under porches, or beneath decks. Opossums are known to move their den site frequently, sometimes every few days, which is a behavior thought to reduce the likelihood of predators locating them. A female with young is one of the few instances where an opossum may remain in a single location for a longer period of time.
Nighttime Foraging and Movement
The primary focus of the opossum’s nightly excursion is finding food and water to sustain its omnivorous diet. They are highly successful scavengers, consuming a wide variety of items, which makes them ecologically beneficial. Their diet includes insects, slugs, snails, fruits, berries, nuts, and carrion, the latter of which helps clean the environment and contributes to a reduced presence of disease.
These animals move deliberately and slowly across their home range, often following established routes along fences, tree limbs, and drainage areas. Although they are not fast runners, opossums are proficient climbers, utilizing their prehensile tail for balance and their opposable hind toes for grip. Their opportunistic feeding habits mean they often explore areas near human dwellings, attracted by accessible food sources such as fallen fruit, pet food left outdoors, and discarded items in unsecured garbage cans.
Understanding “Playing Possum”
The “playing possum” defense mechanism is not a conscious decision but rather an involuntary physiological state known as tonic immobility or thanatosis. This is a last-resort response triggered by extreme fear when the animal is unable to flee or fight a perceived threat. During this state, the opossum collapses onto its side, the body becomes rigid and motionless, and the eyes remain glazed and open.
Accompanying the physical collapse are significant internal changes, including a decrease in heart rate by as much as 46% and a reduction in respiratory rate by approximately 31%. The animal also releases a foul-smelling, greenish fluid from its anal glands, which mimics the odor of decay and can deter a predator that prefers live prey. This state of immobility can last for a few minutes to several hours, with the opossum remaining fully conscious but largely unresponsive to external stimuli until the threat has passed.