As an exotics veterinarian, mothballs are one of the few household products I will flag without any hesitation: they are genuinely dangerous and have no place near a tortoise. People often think of them as a harmless old-fashioned item tucked in a closet, but they are essentially solid pesticide that slowly turns into toxic vapor. That is exactly how they kill moths, and it is why they are hazardous to pets.
Tortoises face a double risk. They can inhale the vapor that fills enclosed spaces, and because tortoises are curious grazers that explore with their mouths, they may also bite or swallow a mothball mistaken for food. With their slow-clearing airways and the fact that mothball vapor soaks into porous bedding and hay, this is a product I tell every keeper to keep completely away from their animal. Here is what you need to know.
Why Mothballs Are Dangerous for Tortoises
Mothballs are made of one of two chemicals: naphthalene or paradichlorobenzene. Both are pesticides that sublimate, meaning the solid slowly turns directly into a toxic gas at room temperature. That gas is what repels and kills insects, and it is also what makes mothballs hazardous to a tortoise sharing the air.
There are two routes of harm. Inhaled vapor irritates a tortoise’s airways, which clear slowly and have no diaphragm to force out irritants. Swallowed mothball is worse, because the chemical is absorbed into the body. The vapor also soaks into porous materials, so hay, substrate, and bedding stored near mothballs become contaminated and dangerous themselves.
Mothballs contain naphthalene or paradichlorobenzene and release toxic vapor as they evaporate. A tortoise can be poisoned by breathing the air around them or by eating a piece. There is no safe way to use mothballs near a tortoise, its enclosure, or its stored food and bedding.
Symptoms of Mothball Poisoning in Tortoises
Signs depend on whether the tortoise inhaled vapor or swallowed a mothball, and how much. Watch for these and act quickly if you see them.
Suspected mothball ingestion or strong vapor exposure in a tortoise needs immediate veterinary attention. Do not try to make a reptile vomit at home. Call your exotics vet or ASPCA Animal Poison Control at 888-426-4435 right away.
Poisoning Timeline
This is a general pattern. Speed and severity depend on the dose and whether vapor was inhaled or a mothball was eaten.
How Much Is Dangerous
Mothballs are concentrated. A single mothball contains a large amount of active pesticide, and I will not invent a precise lethal figure for tortoises because none is established. The safe assumption is that any ingestion or significant vapor exposure is a poisoning risk that warrants a vet call.
Practical Exposure Guidance
Common Sources of Mothballs
Mothballs and their vapor turn up in storage spaces. These are the places I ask owners to check.
Storage Areas
- Closets and wardrobes
- Storage boxes and bins
- Attics and basements
- Drawers with linens
Product Forms
- Classic mothballs
- Moth flakes and crystals
- Moth repellent cakes
- Closet hanging strips
Risky Uses
- Garden pest deterrents
- Shed and garage storage
- Near stored hay or substrate
- Under furniture for pests
What to Do If Your Tortoise Ate Mothballs
If your tortoise swallowed a mothball or was in a space heavy with vapor, treat it as urgent and follow these steps.
Remove From the Hazard
Move your tortoise to clean fresh air immediately and take away any remaining mothballs.
Do Not Induce Vomiting
Never try to make a reptile vomit at home. It does not work safely and can cause harm.
Identify the Product
Find the packaging to learn whether it is naphthalene or paradichlorobenzene, which guides treatment.
Call Immediately
Contact your exotics vet, or in the United States call ASPCA Animal Poison Control at 888-426-4435, without delay.
Get Examined
Take your tortoise in for assessment, as blood and organ effects may need monitoring and supportive care.
Prevention Checklist
Keeping mothballs out of your tortoise’s world is straightforward.
- Never use mothballs in any room your tortoise lives in
- Store hay, substrate, and food far from mothballs
- Keep mothballs in sealed containers in separate areas only
- Never scatter mothballs in gardens your tortoise can reach
- Air out and discard any bedding that smells of mothballs
- Choose tortoise-safe pest control like cedar blocks kept out of the enclosure
- Save your exotics vet and poison control numbers in your phone
Safety note: Mothballs are solid pesticide that release toxic vapor, so keep them completely away from your tortoise and treat any ingestion or heavy vapor exposure as an emergency.
Sources and further reading
What you need to know
Mothballs are highly toxic to tortoises and have no place anywhere near them. They are made from naphthalene or paradichlorobenzene, which slowly release strong fumes designed to kill insects. Those same fumes are harmful to a tortoise’s airways and nervous system, and the solid balls can be deadly if chewed or swallowed. Stored clothing, lofts and cupboards treated with mothballs can hold dangerous vapours for a long time.
Never use mothballs in or near any room housing a tortoise, including in storage above or beside an enclosure, and air out any fabrics that have been stored with them before bringing them near your pet. Signs of exposure include laboured breathing, lethargy, tremors and loss of appetite. Because reptiles deteriorate quietly, do not wait. This is informational guidance only, so contact a reptile vet urgently if you suspect mothball exposure.