No, mothballs are not an effective way to get rid of possums (Didelphis virginiana). While the strong odor of naphthalene or paradichlorobenzene may temporarily deter possums (Didelphis virginiana), the effect is short-lived and unreliable.
Mothballs are regulated pesticides designed for sealed containers, not for outdoor wildlife control. This guide explains why mothballs fail and what actually works for possum removal.
Key Takeaways
- Mothballs are ineffective against possums (Didelphis virginiana). The smell may deter them for a day or two, but they quickly habituate.
- Mothballs are toxic to humans, pets, and wildlife. Using them outdoors is illegal in most states.
- Possums (Didelphis virginiana) are generally beneficial and eat ticks, insects, and carrion. Removal is rarely necessary.
- Exclusion and habitat modification are the only effective long-term solutions.
In This Guide
Why Mothballs Fail Against Possums (Didelphis virginiana)
Mothballs are designed to kill moths and other insects in sealed containers through toxic gas accumulation. They were never formulated to repel mammals like possums (Didelphis virginiana). The reasons they fail include:
- Rapid dissipation: Outdoors, the vapors disperse within hours. Rain, wind, and temperature changes reduce the concentration below effective levels.
- Habituation: Possums (Didelphis virginiana) are intelligent and adaptable. Within 2-3 days, they learn the smell is harmless and return.
- Wrong mechanism: Mothballs kill through toxic gas buildup in enclosed spaces. In open areas, they cannot reach a concentration high enough to affect mammals.
- No barrier: Mothballs create no physical barrier. A possum seeking food or shelter will tolerate the smell.
Health and Legal Risks
- Naphthalene poisoning: Inhaling vapors can cause headaches, nausea, dizziness, and hemolytic anemia.
- Pet toxicity: Dogs and cats that ingest mothballs can suffer vomiting, seizures, and liver damage.
- Soil contamination: Naphthalene residues leach into soil and groundwater, harming beneficial insects.
- Illegal use: Using mothballs outdoors violates FIFRA regulations. Fines can reach $1,000 per violation.
Effective Alternatives
| Method | Effectiveness | Safety |
|---|---|---|
| Secure garbage cans (locking lids) | High | Safe |
| 1/2 inch hardware cloth exclusion | Excellent | Safe |
| Motion-activated lights | Moderate | Safe |
| Live trap and relocation | High | Humane with proper handling |
| Mothballs (for comparison) | Ineffective | Toxic |
For more, read our possum pros and cons guide.
Frequently Asked Questions
Will mothballs keep possums (Didelphis virginiana) away from my garden?
No. Mothballs may deter possums (Didelphis virginiana) for a day or two, but the effect wears off quickly. They are also toxic to soil and plants. Use fencing, motion-activated sprinklers, or capsaicin-based repellents instead.
What smell do possums (Didelphis virginiana) hate?
Possums (Didelphis virginiana) have a strong sense of smell and are deterred by strong odors like ammonia, garlic, and hot pepper. However, scent-based deterrents are temporary and need frequent reapplication. Physical exclusion is more reliable.
What is the best way to get rid of possums (Didelphis virginiana)?
The best approach is to remove food sources (secure garbage, remove pet food) and seal entry points with 1/2 inch hardware cloth. If a possum is already inside a structure, use a live trap baited with canned fish or fruit and relocate it per local regulations.
Are possums (Didelphis virginiana) dangerous to pets?
Possums (Didelphis virginiana) generally avoid pets. They may hiss and bare their teeth as a bluff, but they rarely attack. The greater risk is disease transmission through contact with droppings or urine. Keep pets vaccinated and avoid direct contact.
The Bottom Line
Mothballs are not an effective or safe solution for possum control. They fail because the smell dissipates quickly, possums (Didelphis virginiana) habituate, and outdoor use is illegal.
Focus on removing food sources, sealing entry points with 1/2 inch hardware cloth, and using live traps if removal is necessary. Possums (Didelphis virginiana) are generally beneficial animals that eat ticks and insects, so consider whether removal is truly needed before taking action.
