Rats can be a huge nuisance, destroying property, spreading disease, and contaminating food supplies. If you have a rat problem, you may be wondering if possums can help get rid of them. Here’s a quick answer: Yes, possums do deter rats through direct competition and predation.
However, they aren’t a complete solution on their own.
In this comprehensive guide, we’ll cover everything you need to know about using possums to manage rats. We’ll look at the evidence on whether possums drive away or kill rats, how they interact, ideal habitat conditions, potential drawbacks, and how to attract possums to maximize their rat deterrent effects.
Do Possums Keep Rats Away Through Competition?
There is evidence that possums and rats do compete for some of the same resources like food and shelter. Possums may have some advantages over rats in these competitions. However, rats remain adaptable and persistent, meaning they can still thrive in areas inhabited by possums.
Possums and Rats Compete for Food and Shelter
As omnivores, possums and rats have very similar diets, including human garbage, pet food, garden produce, and small animals. This means wherever food waste is available, possums and rats may compete for those resources.
In urban areas, possums and rats also compete for shelter in attics, walls, and crawl spaces in houses. They seek out dry, warm, secluded den sites for nesting and raising young. As adaptable species, they easily take advantage of buildings for shelter.
Possums Have Advantages Over Rats
Research suggests that between possums and rats, possums tend to be dominant competitors. Some key advantages possums have include:
Additionally, one study found that when sharing the same space, possums will gather most of the available food, forcing rats to go elsewhere to find sustenance [1].
But Rats Can Still Persist Near Possums
Though possums gain certain advantages, rats remain highly adaptable. Urban rats in particular can thrive despite competition from other species. Strategies rats use to persist include:
| – Taking advantage of smaller shelter spaces possums can’t access | – Tracking possum movements and foraging once possums leave an area |
| – Switching to eating possum droppings and waste | – Producing large litters to compensate for possum attacks on juveniles |
So while having possums around can suppress and reduce rat populations through competition, complete eradication of rats is unlikely even with abundant possums present.
Do Possums Hunt and Kill Rats?
Possums are omnivorous marsupials that will sometimes directly prey on rats, though they aren’t as effective at rat control as dedicated predators. The degree to which individual possums hunt and kill rats can vary greatly.
Possums Sometimes Directly Prey on Rats
As opportunistic omnivores, possums will sometimes kill and eat rats when the opportunity arises. They have been observed directly hunting, killing, and consuming rats in both urban and rural environments. However, rats do not make up a major part of the possum’s diet.
Possums prey mostly on insects, snails, rodents, birds, eggs, amphibians, and carrion. They will consume rats, but do not actively hunt them as a primary food source.
Possums Aren’t as Effective at Rat Control as Other Predators
While possums do kill and eat rats, they do not provide effective rat control compared to dedicated rat predators like feral cats, foxes, coyotes, owls, and hawks. This is because:
- Possums are opportunistic omnivores rather than pure carnivores, so rats make up a small portion of their diet.
- Possums do not actively hunt rat colonies and prefer to scavenge alone.
- Possums have a much lower metabolism than similar-sized carnivores, so each individual kills fewer prey.
One study found that an individual Virginia opossum only eats about 1/3 as much as a similar-sized fox. So while possums do kill some rats, they do not seek them out and kill enough to provide effective pest control.
Individual Possums Vary in Their Rat Predation
While possums as a species aren’t great at controlling rat populations, there is significant variation among individuals. Some specific possums may kill more rats than others depending on factors like:
- Age – Younger, more agile possums may hunt more actively.
- Health – Injured or ill possums hunt less.
- Personality – Some possums are naturally more predatory.
- Location – Urban possums encounter more rats.
- Availability of other food – Possums eat more rats when other food is scarce.
So while on average, possums do not provide very effective rat control, it is possible to occasionally come across specific possums that kill a significant number of rats in areas with high rat populations.
Ideal Habitat Conditions for Possum Rat Control
Possums Need Trees and Dense Vegetation
Possums thrive in areas with plenty of trees, dense vegetation, and sources of food and water. According to research from the University of Melbourne [1], possums prefer habitats with canopy cover from trees and dense undergrowth plants.
This provides them shelter and safety, allowing them to construct nests and burrows.
Having lush greenery also brings insects, fruits, buds, and flowers that possums like to eat. So landscapes with diverse plants, shrubs, and trees tend to attract more possums. Conversely, possums avoid open areas without much foliage or cover.
Avoid Too Much Human-Provided Food
It’s important not to intentionally feed wild possums or leave excessive human food sources available. While some supplementary feeding may help possums survive, too much can cause overpopulation and undesirable aggressive behavior [1].
| Good Habitat Management | Poor Habitat Management |
|---|---|
| – Natural vegetation and water sources | – Excess human food waste and pet food leftovers |
| – Limited external feeding | – Overabundant external feeding stations |
As shown above, maintaining a balance is key. The habitat should sustain possums naturally without significant human intervention. Supplemental feeding stations are OK but should be limited.
Consider Possum Nest Boxes
Installing nest boxes specifically for possums can augment natural habitat with more den locations. According to wildlife reproductive biologist Dr. Shannon Hood [2], providing artificial dens helps counteract diminishing tree hollows and ensures possums have safe breeding sites.
Wooden nest boxes can mimic hollow logs and tree cavities possums would normally use. The boxes should contain bedding materials like wood shavings, hay, or leaves. Position them at least 13-16 feet high in trees near dense foliage and food sources. Clean them out annually to prevent parasite buildup.
In one [3] study in Australia, installing nest boxes led to a 25% increase in the local possum population within a year. So when natural dens are lacking, nest boxes can make the habitat more attractive as possums scout out territories.
Potential Drawbacks of Relying on Possums
Possums Aren’t a Complete Rat Solution
While possums do feast on rats and mice, they should not be viewed as a complete rodent control solution. Possums are omnivores and only spend around 20% of their active time hunting. They have varied diets consisting of carrion, insects, snails, frogs, birds eggs, and a multitude of plant foods as well (California Department of Fish and Wildlife).
So you can’t rely solely on possums to clear an existing rat infestation.
Additionally, possums hunt solo and have small territories of around 1-3 acres. So they can only cover a limited area. Whereas rats can roam further and breed rapidly, with females producing several litters per year, each with 6-12 young.
So rats may outpace the predation capacity of any resident possums.
Risk of Disease Transmission
Possums can carry diseases transmittable to humans and pets, primarily leptospirosis and tuberculosis. Leptospirosis bacteria thrive in possum urine. And 5-10% of urban possums may carry bovine tuberculosis (California Department of Fish and Wildlife).
So there is some infection risk from attracting them to your home environs.
Possums Can Become Nuisances Too
While docile when encountering humans, possums still have claws and teeth and can bite or scratch if threatened. And they frequently trigger security lights and raid trash cans for food scraps. Their droppings and urine can stain patios and lawns.
And possums don’t politely rid themselves of garbage offsite, they just drop it where they stand.
They also make loud screeching noises during breeding seasons. And may die in inconvenient locations, creating putrid stench and fly swarms. So an overpopulation of possums lured by abundant rats could create annoyance issues of their own!
Attracting Possums to Deter Rats
Provide Natural Food Sources
Possums enjoy eating a variety of fruits and vegetables. Leaving out produce scraps like apple cores, carrot tops, and old sweet potatoes can lure nearby possums onto your property (1). You can also hang full ears of corn, a natural possum delicacy, from trees.
However, be sure to situate the food at least three feet off the ground so rats can’t easily access it (2). Placing small dishes of pet food out at night may also attract neighborhood possums.
Offer Nesting Sites
Providing potential den sites will encourage possums to stick around. You can create cozy nooks for them by leaving wood and brush piles in place or installing special possum boxes. These wooden nesting boxes offer protection from predators and shelter from the elements (3).
Mount them at least 10 feet high on tree trunks or under eaves. The openings should face away from prevailing winds and measure around 4 inches across. Be sure to include wood shavings or straw inside for bedding.
You can also entice possums to take up residence under your porch or in your shed. Just make sure to eliminate any gaps in the foundation bigger than 4 inches wide so rats can’t get in too. Boost the appeal even more by placing a small bundle of hay inside (4).
Use Strategic Lighting
Some key lighting adjustments can transform your yard into an oasis for possums at night when these nocturnal creatures are most active. Flood lights and bright security lamps may scare them off, so switch any glare-causing fixtures for soft yellow bulbs instead.
You can also install motion sensor spotlights in key possum hangout areas like next to den sites or food sources (5). The sensors will briefly light up the zone when possums go by without keeping the area brightly lit all night long.
In addition, possums feel more secure having the cover of darkness, so they likely won’t venture across large swaths of illuminated ground. Place lighting strategically along pathways and away from prime possum real estate to help them feel at ease.
Just be mindful that extremely dark corners could allow rats to move in undetected.
Conclusion
While possums do compete with and predate on rats, they can’t fully replace dedicated rodent control measures. But attracting possums can be a useful part of an integrated pest management plan. Focus on modifying habitat to favor possums over rats, offer supplemental food and nest boxes, and use strategic lighting to attract these rat-deterring marsupials to your property.
