Do Mothballs Keep Cats Away? The Dangers, Myths, and Safer Solutions

Discover harmless strategies that protect gardens without putting pets at risk.

By Medha deb

Created on Sep 29, 2025

Discover harmless strategies that protect gardens without putting pets at risk.

Do Mothballs Keep Cats Away? Vet-Reviewed Facts & Safer Alternatives

Placing mothballs around gardens or homes as a means to deter cats is an old and widespread tactic. Many people, frustrated with neighborhood or stray cats disturbing flowerbeds or using yards as litter boxes, have tried this method in search of an easy fix. But is it effective, and more importantly, is it safe?

This detailed guide explores whether mothballs can keep cats away, the risks they pose to animals, people, and the environment, and the most humane and effective alternatives available. If you care about pets, wildlife, and your own health, it’s crucial to understand why mothballs are not the solution you may think—and what you should do instead.

What Are Mothballs?

Mothballs are small, round balls or pellets containing chemical pesticides. Their primary use is to protect clothing and fabrics from moths, larvae, and sometimes other insects. When exposed to air, mothballs gradually release a toxic vapor that kills or deters these insects.

Most commonly made of either naphthalene or paradichlorobenzene (PDB).
Occasionally may contain camphor, especially in some countries.
Designed to be used inside tightly sealed containers—not loose in drawers, closets, or the environment.

If you smell mothballs, you’re inhaling their toxic fumes. These chemicals are regulated by environmental protection agencies, and their use outside closed, controlled environments is strictly limited in many regions.

Table: Common Ingredients in Mothballs

Ingredient	Main Use	Toxicity Category
Naphthalene	Traditional moth repellent	Highly toxic
Paradichlorobenzene (PDB)	Modern mothballs	Toxic
Camphor	Some mothballs in Asia	Mildly toxic, but still hazardous

Are Mothballs Effective at Repelling Cats?

The strong odor of mothballs does sometimes deter cats—as well as other animals—but this comes at an enormous cost. The chemicals in mothballs are toxic not only to cats, but also to dogs, children, adults, birds, and beneficial wildlife. Even so, evidence indicates that:

Mothballs are not reliably effective cat repellents. Some cats may avoid the smell, while others do not.
Their use outdoors (for wildlife or cats) is not supported by science.
Placing mothballs in gardens is often illegal due to their toxicity.

Bottom line: while certain animals—cats included—may dislike the scent, the dangers vastly outweigh any potential deterrent benefit.

Health Risks: Why Mothballs Are Dangerous for Cats, Pets, and People

How Are Mothballs Toxic?

Inhalation of fumes is harmful to both pets and people.
Ingestion or chewing is extremely dangerous, especially for animals and children.
Skin contact can also cause health problems.

Symptoms of mothball toxicity in pets (even from limited exposure) include:

Vomiting
Lethargy
Tremors or seizures
Anemia and jaundice (especially with naphthalene)
Respiratory distress or difficulty breathing
Kidney and liver damage
Death in severe cases

Even the residual vapors from spent mothballs pose a longer-term risk, especially to cats, who are more sensitive due to unique metabolic pathways.

Mothballs are especially hazardous if used incorrectly. Attempting to use them as outdoor cat repellents exposes not just targeted cats but also children playing in the area, family pets, beneficial insects, and other wildlife.

How Many Mothballs Can Poison a Cat?

As little as one mothball—if ingested—can potentially poison a cat. The toxic dose depends on several factors:

Type of mothball: naphthalene mothballs are more toxic than PDB-based mothballs.
Size and weight of the cat.
Whether exposure is via ingestion, inhalation, or skin contact.

In general, naphthalene is around twice as toxic as PDB. Older ‘traditional’ mothballs are thus particularly dangerous. Young animals, elderly pets, and those with preexisting conditions are at higher risk.

The Environmental Impact of Mothballs

Using mothballs outside of their registered use—especially scattered in gardens or around the house—poses a threat not just to pets and people but also to the ecosystem.

Chemicals can leach into soil and contaminate vegetables and fruits.
Runoff can enter groundwater or streams, endangering aquatic life.
Other wildlife (birds, beneficial insects) may be poisoned either directly or via contaminated food sources.

Improper use of mothballs to repel mammals, birds, snakes, or insects outdoors may be a violation of local pesticide regulations and is often prohibited.

Why Mothballs Should Never Be Used as a Cat Deterrent

While mothballs were never designed to keep cats away, they became a popular “home remedy” due to their potent smell. However, the reasons not to use mothballs in this way are significant:

Highly toxic to pets, children, and wildlife—risks include serious illness or death.
Ineffective for long-term deterrence—the effect fades as the chemical dissipates, and some cats become accustomed to the odor.
Environmental damage—contaminates soil, water, and plants.
Potential legal implications—illegal or strictly regulated in many jurisdictions.

Veterinarians and wildlife experts universally recommend against using mothballs as animal repellents, including for keeping cats out of gardens, crawl spaces, or other areas.

Legality: Is It Legal to Use Mothballs to Repel Cats?

The Environmental Protection Agency (EPA) and equivalent bodies in other countries strictly regulate the use of mothballs. They are only approved for use as labeled, which means in enclosed containers for insect control—not scattered in open spaces or used to repel animals.

It is illegal in many areas to use mothballs as wildlife or cat repellents.
Fines or other penalties may be enforced for misuse, particularly if they cause harm.

What Should You Do If a Cat Is Exposed to Mothballs?

If you suspect a cat (or any animal) has ingested, inhaled, or come into contact with mothballs, act immediately:

Remove the animal from the source of exposure.
Contact your veterinarian or a local animal poison control hotline without delay.
Observe for symptoms: vomiting, drooling, confusion, tremors, trouble breathing, or yellowing gums/skin.
Do not try to induce vomiting or treat at home unless instructed by a medical professional.

Humane and Safer Alternatives to Deter Cats

Instead of dangerous chemicals, a range of effective and humane options exist for keeping cats away from gardens, flowerbeds, or specific areas:

Motion-activated sprinklers: Cats dislike being surprised by sudden jets of water.
Citrus peels and scents: Many cats naturally avoid citrus, so placing orange or lemon peels can help.
Chicken wire or garden mesh: Laying these on garden beds makes the surface uncomfortable for digging.
Commercial cat repellents: Use only products labeled as safe for pets, people, and the environment.
Ultrasonic deterrents: These emit a sound cats find unpleasant, though effectiveness may vary.
Strategic planting: Choose plants with textures or smells cats dislike (e.g., rue, lavender, or rosemary).

For those seeking natural and non-toxic options, some remedies to consider include:

Coffee grounds: The scent is unappealing to cats.
Mulch with pine cones or stone chips: Makes surfaces less attractive for walking or digging.
Regular removal of cat droppings: Reduces reason for return visits.

Table: Quick Comparison – Cat Deterrent Methods

Method	Effectiveness	Safety
Mothballs	Low to Mixed	Unsafe, toxic, illegal in many places
Citrus Peels	Moderate	Safe
Chicken Wire/Mesh	High	Safe
Motion-activated Sprinkler	High	Safe
Commercial Repellent (pet safe)	Moderate to High	Safe if used as directed

Frequently Asked Questions (FAQs)

Q: Do mothballs keep cats away?

A: Mothballs may deter some cats due to their strong odor, but they pose serious health risks to pets, wildlife, and people, and are not a safe or effective method for cat deterrence.

Q: Are mothballs toxic to cats, dogs, or children?

A: Yes, mothballs are highly toxic to cats, dogs, children, and other animals—risking symptoms ranging from vomiting and lethargy up to organ damage and even death.

Q: Can I use mothballs outdoors or in the garden to deter cats?

A: No, using mothballs outside of their labeled usage (in a sealed container for fabric protection) is not only dangerous but often illegal due to risks of environmental contamination and poisoning.

Q: What should I do if my pet comes into contact with mothballs?

A: Remove access to mothballs immediately, observe for any symptoms of poisoning, and seek veterinary help as soon as possible. Do not attempt home remedies before consulting a professional.

Q: What are safer alternatives to keep cats out of my garden?

A: Consider humane measures like chicken wire, citrus peels, motion-activated sprinklers, or planting cat-repellent herbs. Always select non-toxic deterrents approved for use around pets and people.

Final Thoughts

Mothballs are neither a humane nor a safe way to deter cats. Their toxic fumes, strong potential for harming pets and children, and the risk of environmental contamination far outweigh any limited deterrent effect. Responsible homeowners and animal lovers should avoid mothballs as a repellent for cats and instead opt for proven, non-toxic, and effective methods. By doing so, we can create safe spaces for our pets, our families, and our communities.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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