Will Mothballs Keep Possums Away? What to Do Instead

If you are dealing with possums around your home, you have probably wondered, will mothballs keep possums away. The short answer is no. Mothballs can smell strong, but that does not translate into reliable protection, and using them can create health and contamination problems.

For more help, see our What Mothballs Repel (And Why They Often Fail) for Pests guide.

The short answer: mothballs are not a good possum repellent

People reach for mothballs because the odor is intense, and it feels like it should “push pests out.” In reality, possums are opportunistic, and they focus on food, water, and shelter. When the smell fades or the possum finds an easier route to a meal, the visits restart.

Why people try mothballs in the first place

Mothballs are familiar, inexpensive, and widely sold for moth control. When you see droppings, damage, or nighttime visits, it is tempting to treat the symptoms with a strong-smelling chemical. People also assume any harsh odor will drive animals away, especially if they have heard mothballs work for other pests. The problem is that possums do not react the same way, and an odor alone does not address why they are at your property. If your yard or home offers food scraps, easy climb access, or an enclosed shelter, mothballs are a weak fix.

Why the effect is weak, short-lived, or unreliable

Mothball odor needs confinement to have any strong impact, and even then the effect is inconsistent around open outdoor spaces. Wind, rain, and temperature changes spread the chemical smell, so the possum stops “associating” your area with a threat. If there is a steady food source, the animal will keep returning and using other routes. You may notice fewer visits for a short window, then the pattern returns once the odor dissipates. Relying on scent also means you are not removing the drivers, food and shelter, that keep possums coming back.

Why this method can create bigger problems than it solves

Mothballs introduce toxic chemicals near areas where people, pets, and wildlife move. That creates risk even if you think you are using them “in moderation.” Residue and contaminated surfaces can occur, especially near entries, sheds, or crawl spaces. In a garden, chemical exposure can also interfere with composting and soil health, and it can harm non-target animals. Instead of solving the root issue, you spend time and money on a product that does not hold up and can add new hazards to an already frustrating situation.

Why mothballs are a poor choice around homes and gardens

Mothballs are not designed as outdoor wildlife deterrent products, and that matters. The chemicals can be hazardous, and the practical outcome is inconsistent. You also have to store and handle them, which increases the chance of accidental exposure.

Health risks for people, pets, and wildlife

Mothballs contain chemicals that are harmful if inhaled, touched, or ingested. Keep in mind that curious pets and small children can access stored items, or contact contaminated surfaces if mothballs are placed incorrectly. Wildlife can also be affected if the chemicals contact fur or paws, or if animals ingest residues while foraging. Instead of just “deterring” possums, you may create a broader safety problem around your household. If you have ever found mothballs knocked over, chewed, or scattered, that is a sign you should stop using them and switch to safer prevention.

Chemical exposure in enclosed spaces and near entry points

The risk rises near entry points, like under decks or in roof cavities, because chemicals can concentrate in enclosed spaces. You may also seal an area thinking you are blocking entry, then trap an animal inside, creating additional cleanup and potential exposure. Possums that gain access to those areas can drag chemical residue through other parts of the home. Even if you do not see a possum, you can still increase exposure for people working in those areas. The safer approach is to keep possums out by blocking access and removing attractants, not by introducing toxins into the structure.

Odor drift, residue, and contamination concerns

Outdoor odor drift is unreliable for deterrence, but it is still enough to contaminate nearby surfaces. Mothballs can leave residues, and the smell can cling to fabric, tools, and storage totes. If you place mothballs in sheds or near gardens, you can contaminate items you use later, like potting soil supplies, garden gloves, or bedding. It is also difficult to know where the chemicals travel after rain or foot traffic. Strong odor is not the same as effective wildlife control, and the contamination downside is the reason many homeowners abandon mothballs for prevention methods that do not leave toxic residue behind.

What actually attracts possums to your property

Possums stay where resources are steady. If your place offers food, shelter, or safe travel routes, the animal keeps coming back even when you try a quick chemical fix.

Food sources that are easy to overlook

Food is the biggest driver. Common triggers include unsecured garbage, pet food left outside, fruit from fallen branches, and birdseed scattered on the ground. Compost piles attract insects and plant matter, which supports possums and the prey they follow. Even if you do not intend to feed wildlife, small food sources add up at night when possums forage. Focus on the “night buffet,” the items that remain available after dark, not the occasional treat. When food is removed, possums often move to a property with fewer easy meals.

Shelter spots such as decks, sheds, and roof cavities

Possums look for enclosed, quiet spaces to rest and raise young. Under decks, in sheds, behind shutters, and in roof cavities can offer protection from predators and weather. Overgrown shrubs and cluttered storage areas create hiding places, and they also provide travel cover from one spot to the next. If there is already a den, simply adding odor will not solve the shelter issue. You need to make the structure inaccessible by sealing entry points with proper exclusion methods. Removing attractants helps, but blocking safe harbor is what stops repeated visits.

Water, warmth, and safe travel routes

If there is water nearby, like from a leaking hose bib, dripping air conditioner unit, or outdoor pet water bowl, it becomes a draw. Warm spots also matter, including vents that release heated air or sheltered areas that stay dry during storms. Possums also prefer safe routes, cover along fences, dense groundcover, and pathways under decks or through tall weeds. Clearing travel cover forces them to spend more time exposed. Addressing water leaks and removing hiding cover makes your property less comfortable for overnight visits.

Better ways to keep possums away without mothballs

The most effective strategy is simple, remove attractants and block access. Add humane deterrents where they help, like lights or motion sprinklers, and keep the changes consistent.

Remove food and seal garbage tightly

Start with the easiest win. You want to eliminate food access, especially at night when possums are most active.

Bring bins in promptly after collection and store them in a locked area or garage.
Use a lidded, sealed bin with a tight-fitting lid, and keep trash bags sealed at the knot.
Clean up fallen fruit and remove scraps, especially under fruit trees and around compost areas.

Check for pet food bowls left outside overnight and bring them in after feeding.

When food stops being available, possums move on faster. This also reduces the chance of attracting other pests that feed on leftovers.

Secure pet food, fruit drop, and compost

Pet food, fruit drop, and compost are high-value resources. You do not need to “fight the animal,” you need to remove the pantry.

Store pet food in sealed, lidded containers, and keep them off the ground.
If you have fruit trees, sweep or collect dropped fruit daily.
Keep compost covered with a tight lid or mesh cover, and avoid adding meat, dairy, or oily food.

Empty outdoor compost bins before they become fully accessible to wildlife.

When these resources are managed, possums spend less time near your house. This approach also helps you avoid chemical hazards that come with mothballs.

Block access to crawl spaces, roofs, and gardens

Exclusion is what prevents return visits long term. Possums can squeeze through surprisingly small gaps, so you need to seal entry points correctly.

Identify entry openings by looking for rub marks, droppings, and tracks under decks, eaves, and around vents.
Use hardware cloth (metal mesh) to cover gaps and openings, and fit it securely so there is no flexible edge.
Do not permanently seal an area if a possum could be inside, use a controlled exclusion approach or get help.

Trim back garden contact points that create a “ladder” to rooflines and ledges.

Once entry points are blocked and the property is no longer easy to access, you reduce repeat visits dramatically.

Use motion lights, sprinklers, or humane deterrents

Behavior-based deterrents add pressure, especially at the moments possums approach. Use deterrents alongside prevention, not as the only fix.

Install motion-activated lights near common entry areas like deck stairs and shed sides.
Place motion-activated sprinklers aimed at pathways they use, adjust sensitivity to reduce false triggers.
Use humane scare devices per manufacturer instructions, focusing on high-traffic routes rather than random placement.

Reposition deterrents after a week if you still see consistent tracks.

Lights and water disrupt their routine and encourage them to find a safer route elsewhere. Keep everything humane, and avoid toxic methods.

How to make your yard less inviting to possums long term

Long-term relief comes from reducing shelter, climb access, and easy hiding spots. Keep the yard tidy in the areas possums travel through most.

Trim branches and reduce climb paths

Possums climb well, and they use overhanging branches as bridges. If they can reach a roofline from a tree or shrub, entry becomes much easier.

Trim branches back from roofs, gutters, and fences so there is clear space.
Remove “ladder” vegetation, tall shrubs touching walls or edging close to eaves.

Cut back vines and groundcover that create hidden routes to entry points.
Keep plants pruned so you can see the wall and foundation edges clearly.

This makes it harder for possums to reach roof cavities and attic openings, and it also reduces the covered paths that let them move without being exposed.

Clean up hiding places and nesting materials

Clutter equals safety to a possum. Boxes, yard debris, and nesting material make your property feel like a protected den.

Store firewood and stacked items off the ground, and keep spacing from walls.
Clear leaf piles, brush piles, and long grass near foundations and under decks.

Remove old furniture, tarps, and unused equipment that collect shelter.
Bag and remove nesting materials, like loose insulation or fabric scraps, if you find them.

A cleaned-up perimeter reduces the chance of nesting and discourages denning. It also makes it easier to spot new entry openings.

Protect chicken coops, vegetable beds, and bird feeders

High-value areas attract constant visits. If you have chickens, gardens, or feeders, secure them in a way that denies access at night.

Cover chicken runs with sturdy wire, and ensure gaps under doors and vents are sealed with hardware cloth.
Use raised beds with fencing to stop digging and nibbling.

Bring bird feeders in at night or use a feeder design that limits seed scatter.
Clean up spilled seed and fallen produce around feeders and garden edges.

When these areas are protected, possums stop viewing your yard as a reliable source of calories and shelter.

Choose plants and barriers that reduce nuisance visits

You cannot plant a “perfect” barrier that repels possums like a magic shield, but you can reduce cover and access points.

Use low, dense groundcover instead of tall, dense cover near walls and fence lines.
Install physical barriers along key routes, like along deck sides and fence edges.

Add edging or trim vegetation so gaps are visible and climb access is limited.
Avoid letting plants touch gutters, siding, or roof edges.

If possums cannot move through hidden cover, they tend to abandon routes and look elsewhere.

What to do if possums keep coming back

Persistent visits usually mean there is still a food source, an entry point, or an occupied shelter. Address those items directly instead of repeating deterrents.

Check for a den, nest, or repeated food source

Start by confirming what is driving the behavior. If the possum is nesting, deterrents and odor do not solve it quickly.

Inspect common areas like under decks, sheds, roof eaves, and around foundation gaps.
Re-check areas where food is likely, including garbage storage, pet bowls, birdseed, and compost.

Look for repeated tracks and droppings in the same spots, not random mess across the yard.
Search for damage patterns, like chew marks around vents, to find the active entry.

Denning is a common reason for return visits. Once you locate the driver, you can remove it safely.

Look for signs of young or an occupied shelter

If young are present, sealing access can create serious welfare issues. You need to know what is inside before you change the environment.

Watch for repeated adult activity and consistent entry and exit paths.
Look for faint sounds or movement in enclosed spaces under decks or inside roof cavities.

Check for droppings and nesting material near the opening.
Treat any evidence of young as a reason to get professional help for proper exclusion.

This is also where you should avoid aggressive trapping or sealing without guidance, because it can trap the animal inside.

When to call wildlife control or a licensed professional

Call for help when the possum is established, the structure is complex, or you suspect young. Licensed professionals can handle exclusion and safety steps correctly.

Contact a professional if you find an occupied den inside walls, roof spaces, or crawl spaces.
Get assistance if you cannot locate the entry point after inspection.
Choose help if multiple visits continue despite removing food and blocking accessible gaps.

Call immediately if you see illness signs, injured wildlife, or aggressive behavior.

Professional wildlife control can remove the risk of improper sealing and help you implement correct exclusion so the problem stops for good.

Safe removal and prevention checklist

Use this checklist to reduce risk on day one and prevent the next round of visits. It focuses on removing attractants, identifying access, and using humane deterrents safely.

A simple step-by-step plan for the first 24 hours

Remove all outdoor food access, take in pet food, secure garbage bins, and collect fallen fruit.
Pick up scattered birdseed and empty water sources, like dripping hoses and outdoor pet bowls.
Set up motion lights or motion-activated sprinklers at the paths you see possums using.

Inspect the perimeter at night for active entry points, using a flashlight to look for rub marks and openings.
Temporarily block large visible gaps with something secure you can remove safely, but do not permanently seal a suspected occupied shelter.

This plan reduces immediate incentive to stay and buys you time to do correct exclusion.

What to avoid so you do not make the problem worse

Do not use mothballs, mothball odor is unreliable for possums and can expose people, pets, and wildlife to toxic chemicals.
Do not permanently seal an opening if you think a possum may be inside, you can trap it and create a cleanup and welfare crisis.
Do not leave traps set without proper knowledge, trapping without correct handling can increase harm and legal risk.

Do not ignore the food source, deterrents fail if the pantry remains open.

Avoiding these mistakes prevents repeat visits and reduces safety concerns.

How to monitor whether your fixes are working

Check the same entry areas each morning for new droppings, fresh tracks, and rub marks.

Review camera footage if you have a motion camera, compare visit frequency before and after changes.
Note whether deterrents trigger at the times you see activity, adjust sprinkler aim and light placement if needed.
Reinspect food zones daily for one week, especially garbage storage, pet feeding areas, and garden edges.

This tells you whether you removed the attractants and whether access points still exist. If activity continues in the same spots, focus on exclusion and professional help.

Frequently Asked Questions

Do mothballs keep possums away?

Not reliably. Mothballs may smell strong, but they are not a dependable possum deterrent and can pose safety and environmental risks.

Do mothballs repel possums for good?

No. Any effect is usually temporary at best, and possums often return once the odor fades or they find food and shelter.

Are mothballs safe to use outside for possums?

They are generally a poor choice. They can expose people, pets, and wildlife to harmful chemicals and may violate local rules depending on how they are used.

What is the best way to stop possums from coming back?

Remove food sources, secure trash, block entry points, and use humane deterrents like lights or motion-activated sprinklers.

What should I do if a possum is living under my deck or in my roof?

Identify the entry point, avoid sealing it if an animal may be inside, and contact a licensed wildlife professional if needed.