Mothballs for Groundhogs: Risks and Safer Options

You’re seeing fresh holes, chewed plants, and tracks around your yard, and you want to know one thing. Will mothballs keep groundhogs away, or is that just an old tip people repeat? The truth is that mothballs are unreliable outdoors and come with real risks you do not want in a home yard. If you want results, focus on prevention and removal methods that target how groundhogs live, not just what they smell.

For more help, see our Mothballs for Yard Animals: Risks, Limits, and Safer Options guide.

Why people reach for mothballs in the first place

People reach for mothballs because they think the strong odor will act like a repellent. When you see damage right near a burrow or favorite feeding spot, it feels logical that a harsh smell should push the animal away.

What groundhog damage looks like in a yard

Look for groundhog activity near edges and cover, like under decks, along fence lines, or near sheds. Common signs include burrows with cleared entrances, flattened grass around the opening, and fresh soil piles. You may also see clipped stems and leaves from garden plants, flowers, and vegetable beds.

Groundhogs can be picky about what they eat, so the damage often concentrates on certain plant types while other areas look intact. They also leave behind tracks and sometimes grease marks along frequently used paths. If you spot a new burrow and feeding damage above ground at the same location, it is a strong indicator you are dealing with a groundhog.

Why the mothball trick keeps getting recommended

Mothballs are notorious for a powerful odor, and people remember deterrents that worked for other pests. In some cases, the animal may reduce activity for a short time after encountering the smell, or a person may notice results after a change they did around the same time.

That is why the story spreads, even when the outcome is not consistent. Groundhogs can change their behavior based on food availability, weather, and nearby threats. Odor-based “solutions” often fail once the animal learns the area is not dangerous or once the smell fades outdoors.

Groundhogs vs. gophers: don’t mix up the pests

Groundhogs and gophers both dig, but their patterns and damage differ. Groundhogs create larger, more obvious surface entrances, often near structures like fences, decks, and outbuildings. They also leave more visible above-ground feeding damage because they forage on plants.

Gophers tend to create extensive tunnel systems with smaller holes and mound-like earth piles, often in open lawn areas. If you treat gophers with groundhog tactics, you may end up chasing the wrong problem. Correct identification matters because the control method depends on how the animal uses the property.

Do mothballs actually work on groundhogs?

Mothballs are not a reliable groundhog deterrent. Even when the smell reaches the animal, it does not reliably stop feeding or keep a groundhog from returning to a burrow.

What the odor may do, and what it usually cannot do

The odor can discourage an animal briefly if it comes in contact with the groundhog’s immediate route or if wind pushes the smell into its path. However, it does not create an actual barrier, and groundhogs can move around scents, dig through treated areas, or return once the odor weakens.

Mothballs also do not address the real attraction, like food, cover, and safe burrow space. If the yard still offers meals and a protected home, the groundhog’s behavior usually wins over the smell.

Why some people think they saw short-term results

Short-term “wins” happen for several reasons. A groundhog may already be temporarily absent, then comes back later, making it look like the mothballs did the job. Other factors can change at the same time, like mowing, garden cleanup, or the use of fencing.

Another common reason is that the smell is strong right after placement, then fades. If the animal avoided the area for a day or two, the story becomes “it worked,” even though the effect does not last.

When a groundhog is likely to ignore the smell

Groundhogs commonly ignore odor-based deterrents when there is food nearby and the burrow feels safe. If the mothballs are not positioned correctly to reach the animal’s route, the smell may dissipate before it has any meaningful impact.

Once the groundhog has established a routine path between the burrow and feeding sites, it can bypass repellent areas. In many yards, groundhogs also adapt quickly, especially when they can shelter in thick cover or under structures.

The risks of using mothballs outdoors

Mothballs are designed for storage in enclosed spaces, not for open-air wildlife control. Using them outside exposes people, pets, and the environment to chemicals that the label does not intend for yard use.

Why mothballs are not meant for open-air pest control

Mothballs release chemicals intended to stay contained and active in storage. Outdoors, wind, sun, and rain dilute and disperse those chemicals, so you get less effect and more spread. The label use case is indoor or sealed storage, not placement in a yard around burrows.

When people put mothballs near entrances, they can also physically attract digging behavior, since the animal is investigating the area. That creates even more direct exposure risk for anyone who might later handle or disturb the area.

Health concerns for children, pets, and wildlife

Mothballs pose ingestion and contact hazards. Children and pets are especially vulnerable because they can access baited areas quickly, pick up contaminated materials, or chew on objects near burrows.

Wildlife can also be exposed when mothballs get scattered, crushed, or carried off. Even if the groundhog does not eat them, other animals in the yard, like birds, cats, dogs, or scavengers, can come into contact with residues.

Soil, plant, and water contamination concerns

When mothballs sit outdoors, chemicals can leach into soil or spread through runoff. That can impact plant health in nearby beds and harm beneficial organisms in the ground.

If you have a slope leading toward a storm drain, ditch, or water feature, the risk increases. It is not worth treating a burrow like a chemical disposal site when you can solve the problem with safer, targeted methods.

Legal and label-use issues homeowners often miss

Most mothballs have label instructions tied to specific uses. Using them outdoors for wildlife control can violate the product label and local rules about chemical application.

Because enforcement depends on location, the practical risk is you end up responsible for misuse. The safest approach is to follow label directions and switch to control methods that are designed for outdoor pest management, including humane options and exclusion.

Safer ways to get rid of groundhogs

Safer control starts with removing what the groundhog needs and blocking what it uses. Focus on food access, shelter, and entry points, then use humane exclusion so the animal cannot simply move back into the same space.

Remove food sources and hiding places

Start by making the yard less inviting. Clear or secure tempting food, including fallen fruit, birdseed, and pet food left outside.

Then reduce cover. Trim dense ground cover near the burrow area and remove clutter where the groundhog can hide. If a garden is the main food source, protect it with sturdy barriers and stop leaving plants accessible overnight.

Number one change is consistency. If you remove food one day and leave it the next, the animal learns the pattern.

Remove fallen fruit and keep garbage covered.
Store birdseed and pet food in sealed containers.
Trim dense plants and eliminate hiding spots near the burrow entrance.
Pick a protected feeding route using fencing instead of open access.

Use fencing that a groundhog cannot easily dig under

Groundhogs can dig under weak edges, so fencing needs to address the bottom. The goal is a barrier that forces the animal to stay out, not just a line it can crawl beneath.

Use hardware cloth or sturdy welded wire, not thin mesh. Extend the fence below grade (bury it) or add an angled outward “skirt” so digging does not create an easy escape route into your yard.

Install sturdy fencing with hardware cloth or welded wire.
Bury the bottom edge at least several inches, and keep gaps small.

Add a outward-facing angle or apron to reduce under-digging.
Inspect after storms and repair any gaps fast.

Try exclusion and one-way exit methods

Exclusion works when you prevent re-entry after the groundhog leaves the burrow. You need a way for the animal to exit, but not to come back inside.

Use a one-way door method, often called a one-way exclusion device. Place it only after the animal is actively away, and seal the rest of the openings except the exit point, so the groundhog cannot choose a different entrance.

Identify all active openings in the burrow.
Install a one-way exclusion device on the main entrance.
Seal off other openings securely, leaving only the exit route.

Leave it in place until you see activity stop and then remove and secure the burrow openings.

Consider motion-activated deterrents and habitat changes

Deterrents can help when they create immediate discomfort and disrupt routines. Motion-activated lights or sprinklers can startle a groundhog when it approaches the protected area, especially at night when it feeds.

Pair deterrents with habitat changes, so the animal has fewer reasons to return. Keep the area around fences and plantings trimmed so there is less cover, and use lighting that covers the approach route.

Use a motion-activated light or sprinkler to disrupt feeding times.
Reduce cover near the entry points so the animal is exposed.
Keep plants protected with barriers rather than relying on deterrents alone.

Adjust the setup after observing when the animal approaches.

When repellents make sense, and when they don’t

Repellents can be useful as part of a broader plan, but they should not be your only strategy. A repellent works best when you pair it with exclusion or removal of attractants.

How to choose a humane repellent strategy

Choose repellents designed for outdoor use and follow the label exactly. Look for products meant for groundhogs or nuisance wildlife, and use them around the approach area, not buried into the burrow.

For humane strategies, prioritize methods that discourage behavior without creating a toxic exposure risk. Motion-activated devices and habitat changes often fit this category better than chemical options like mothballs.

Pick a repellent labeled for outdoor nuisance wildlife control.
Apply only to the areas the groundhog uses to travel and feed.
Combine repellent use with fencing or temporary barriers.
Keep the schedule tight, matching the product’s reapplication instructions.

Why consistency matters more than strong smell

A strong odor is not the same as long-lasting control. Outdoors, scent disperses and conditions change, so you need repeat applications or a system that keeps the animal unsettled through behavior disruption.

Consistency also matters because groundhogs follow routines. If you stop applying the repellent after the yard looks “quiet,” the groundhog often returns when it resumes normal feeding patterns.

Track the problem for a couple of days after applying deterrents. If feeding continues near the same spot, move to exclusion and barriers rather than escalating chemicals.

Signs the problem has moved beyond DIY control

DIY control usually fails when the burrow is established and the animal keeps returning. Signs include multiple burrow entrances, damage spreading to new areas, or repeated night-time feeding despite deterrents and cleanup.

If you are dealing with a family group, you may see juveniles and continued digging. When you cannot secure safe exclusion or the damage impacts structures, call wildlife control.

Multiple active entrances keep reopening despite attempts to deter.
Damage persists after consistent cleanup and deterrent use.
The burrow is under a structure you cannot safely block.
You have ongoing activity at night and no clear stop pattern.

If the burrow is active, what to do next

Active burrows need a plan that prevents re-entry. The safest path is to confirm the active entrance, use humane exclusion, then block access in a way that matches the local rules.

How to confirm you’re dealing with a groundhog burrow

Start by checking for fresh signs at the entrance, like new soil, scuffed edges, and recent digging near the opening. Groundhog burrows often have larger entrances and a clear path to feeding areas.

Next, look for feeding damage above ground near the burrow, especially clipped plants and garden losses. Use a quick observation window at dawn or dusk to see whether the animal is actively moving in and out.

Avoid assuming based on one hole. Correct identification and active status determine the next step.

When to call wildlife control or a licensed professional

Call professionals if the burrow is under a deck or structure where exclusion is tricky, or if you cannot safely access and assess all openings. Also call if you suspect you may be dealing with a protected wildlife situation in your area.

Wildlife control can install proper exclusion, manage timing, and ensure the work matches local regulations. That matters because improper blocking can trap an animal inside the burrow, which is a serious welfare issue.

How to prevent re-entry after removal

Prevention is where most DIY efforts break down. Even if you remove the animal, it can return if openings remain accessible or if there are hidden alternative entrances.

After exclusion, close openings in a way that prevents digging back in. Reinforce the barrier around the area, and keep food and cover changes in place so the groundhog has no reason to come back.

Identify and address every active opening, not just the main entrance.
Use barriers that stop under-digging at the perimeter.
Seal and reinforce after the animal is out, following local guidance.

Keep the yard unattractive, with secured food and trimmed cover.

Quick comparison: mothballs versus better options

When deciding how to respond, compare the real outcomes, not the idea of “repelling smell.” In most yards, mothballs lose on both reliability and safety.

Effectiveness

Mothballs do not reliably keep groundhogs away for long. Any effect is temporary because the odor disperses and groundhogs can shift routes or return when food and shelter remain available.

Better options like exclusion, fencing, and habitat changes target the reasons the groundhog stays. Motion-activated deterrents can help reinforce those steps by disrupting feeding behavior.

Safety

Mothballs are a poor choice because they expose people, pets, and wildlife to chemicals outdoors and can contaminate soil and water.

Fencing, exclusion, and non-toxic deterrents present far lower risk when used correctly. They also avoid spreading chemicals across the yard.

Cost and effort

Mothballs seem cheap upfront, but frequent replacement, cleanup, and lingering contamination concerns add effort. If the groundhog keeps returning, you pay the cost in repeat damage.

Fencing and exclusion may cost more at the start, but the work is targeted and reduces recurring losses.

Best use cases

Mothballs are meant for sealed storage uses, not outdoor burrow control. For groundhogs, use safer outdoor strategies that physically stop access and reduce attractants.

Choose humane repellents and deterrents only as part of an overall plan, not as a substitute for exclusion and barriers when the burrow is active.

Frequently Asked Questions

Will mothballs keep groundhogs away?

Usually not for long. Any effect is often temporary, and the safety risks make mothballs a poor choice for outdoor groundhog control.

Do mothballs repel groundhogs or gophers?

They may smell unpleasant, but that does not reliably drive either animal away. Groundhogs and gophers often ignore or quickly adapt to odor-based deterrents.

Are mothballs safe to place near burrows?

No. Mothballs are labeled for specific indoor storage uses, and placing them in yards or burrows can expose people, pets, wildlife, soil, and water to harmful chemicals.

What is a better way to get rid of groundhogs?

Exclusion, fencing, habitat changes, and one-way exit methods are typically more effective and safer. Severe infestations may need licensed wildlife control.

How can I tell whether I have a groundhog or gopher problem?

Groundhogs usually make larger burrows near sheds, decks, or fences and leave visible feeding damage above ground. Gophers create different tunnel patterns and mound shapes, so identifying the pest correctly matters before choosing a control method.