In your neighborhood at night you may see an animal with stiff white and gray hair, naked ears, a long scaly tail, and opposable thumbs on each hind foot that it uses for climbing. Opossums are about 2-3 feet long and weighs between 4-10 pounds. They are solitary animals with simple needs: nearby food, water, and a safe, dark place to sleep during the day.
Opossums have existed since the days of the dinosaurs. They are the only marsupials native to North America. Like kangaroos, marsupials carry and nurse their young inside their mothers’ abdominal pouch. Baby opossums reach this pouch by traveling down the birth canal as bee-size embryos and crawling up 2 inches to their mother’s pouch, a process that takes about 10 minutes. On reaching the pouch they attach themselves to one of thirteen nipples that swell to secure the attachment and provide them with nourishment for over two months. When they grow to 4-5” they leave the pouch and travel on their mother’s back. At six months when they are 7” long nose to rump (not including their tails), they leave their mother and live on their own.
Do not be afraid of opossums. They tend to be nonaggressive and shy. They will rarely fight and won’t harm us if we leave them alone to do what they do best – clean up our neighborhoods by eating just about anything they find: insects, snails, slugs, grubs, cockroaches, ticks, garbage, mice, carrion, pet food left out, fruits, grains, even snakes. According to research by disease ecologist Dr. Rick Ostfeld of the Cary Institute, opossums can consume in one season as many as 5,000 blacklegged ticks, carriers of Lyme Disease.
If threatened, opossums first try to escape but move very slowly. However, if they are cornered on the ground they growl, hiss, and bare their 50 sharp teeth, hoping to frighten predators away. Always keep people and pets away from opossums. In defense, as a last resort, they emit a smelly substance from their anal glands, drool, and defecate. Their bodies enter into a catatonic state for a while, in which their nervous system automatically lowers their heartbeat and reduces their breathing, making them appear dead and causing some predators to lose interest. This condition is popularly known as “playing ‘possum.” Opossums lying in the road who appear to be dead may only be “playing ‘possum”. One easy way to reduce black legged ticks in a community is to warn drivers to avoid striking opossums, including those who appear to be dead.
Opossums’ lives are short (up to 3 years) and difficult. Their natural predators—dogs, foxes, hawks, and owls plus automobiles claim the lives of many. Opossums’ instinct to play dead when sensing danger cannot protect them from advancing vehicles. If you are driving and see an opossum in the road that appears to be lifeless make every effort to avoid it.
If you find an apparently dead opossum, leave it for a while in a quiet place with a clear exit path, and allow it to escape on its own. If you find an apparently dead opossum by the road that has been struck by a vehicle and it appears to be a female with babies in her pouch, put on protective gloves. Use a towel to help transfer the dead mother to a box with a lid, and take her to the nearest wildlife rehabilitation center. (Protective gloves, a towel, and a box with a lid that are kept in one’s vehicle can come in handy.) If a dead mother opossum with live babies in her pouch is taken immediately to a wildlife rehabilitation center, the babies may be saved. Exercise great caution when picking up even an apparently dead opossum. Opossums have very sharp teeth.
A list of wildlife rehabilitation centers in the United States is available at the National Wildlife Rehabilitators Association.
If opossums travel through your yard, keep your dogs in at night. Turn on the outdoor lights and take the dogs out on a leash for necessary bathroom breaks. Leashing your dog at night, even when you take the dog outside for potty breaks, also prevents encounters between your dog and other nocturnal wildlife such as raccoons and skunks.
The presence of an opossum in your yard can mean that there is something nearby that it wants: a dark place under a deck or house, tool shed, garages, or attic to shelter it during the day when it sleeps; food such as vegetable gardens, compost piles, dishes of pet food left outside, carrion, fruits, nuts, and small mammals such as mice; and a source of water. If your property does not provide an opossum with these three amenities (shelter, food, and water), it will simply pass through your property on its way to a property that does provide them.
Keep in mind that opossums do not harm your garden so it is best to let them wander through it in safety and leave them alone. If you wish to discourage visits from opossums, keep reading.
Following these suggestions will also discourage visits from roof rats, raccoons, and skunks.
Trim back overgrown shrubbery and leave at least 5 feet between your rooftop and trees that overhang it. Pick up fallen fruit frequently. Stack your firewood so that there are no openings that lead to a potential den. Have tight fitting lids on your garbage cans and on your compost bin. Feed pets indoors and put away any uneaten pet food. Close and lock pet doors at night, keeping the cat indoors.
Strategies include turning on a light, playing a radio, closing access holes with a tight cover, and placing a rag in a bowl and saturating it with ammonia.
If opossums have found an opening to your crawlspace under the house you need to find the openings that allow it to enter the crawlspace. Try placing a light under the house, and play a radio under the house during the day to encourage the opossum to move on.
Before permanently closing access holes possibly used by an opossum, lightly sprinkle and smooth a 4” patch of flour outside the access hole. The flour will record the opossum’s footprints when it goes out at night and indicate which opening the opossum uses. Before the next time the opossum leaves for its nightly food search close all openings (except the one that had the opossum’s footprints) with 1/4-inch hardware cloth. The hardware cloth cover will also keep out roof rats and mice. Place rumpled paper or soft netting that an animal can push aside in the remaining access hole. The next time the opossum leaves for its nightly activity and you see its footprints in the flour leading away from that access hole, immediately close up the hole with 1/4-inch hardware cloth, before it returns from its nightly food search.
Ammonia-soaked rags placed in shallow bowls near the den area can emit strong odors to discourage an opossum from remaining. If you combine closing up access holes with other deterrents such as radio noise, light, and ammonia, the opossum will soon look for another place to sleep.
Protect Fruit and Nut Trees
Wrap fruit and nut tree trunks with 18” wide sheet metal up to 5-6 feet above the ground, and collect fallen fruit and nuts.
Sheet metal 18-inches or wider wrapped around tree trunks up to 5 feet above ground will discourage opossums from climbing trees. Never use sticky substances that are designed to trap permanently animals that touch or walk on them. Sticky products can harm and kill a wide variety of wildlife, including birds. Terrified critters that become stuck sometimes tear off their limbs attempting to escape.
Fence opossums out of a specific area.
If you want a specific area of your garden to be off-limits to opossums, you can construct a fence of poultry wire 4 feet high with the top 12-18 inches bent outward away from the garden and minimally attached to any support. Without support, the fence will bend under the weight of an opossum and make it difficult to climb over it.
Keep chickens safe from opossums.
If you have chickens on your property it is essential to provide a predator-proof house and yard for them. Opossums prey on chickens but do so less than raccoons.
Chickens and other small animals such as domestic ducks and rabbits are extremely vulnerable to predators. They depend on us to keep them safe. Building a predator-proof chicken house and chicken yard can prevent attacks on chickens that can traumatize your family and cause great suffering to your chickens. Find a detailed description of predator-proof housing for chickens here.
We owe opossums our gratitude for helping to keep our gardens clean and for eating insects and garden pests such as snails, slugs, and ticks. Lucky is the resident whose garden is visited by an opossum.