The #1 tick and mosquito prevention tool you're probably not using
Permethrin-treated clothing kills ticks and mosquitoes on contact — they don't need to bite through the fabric. A tick landing on a treated pant leg is dead within seconds. This is fundamentally different from repellents which just discourage landing. The effect persists through 6+ wash cycles because permethrin binds to fabric fibers.
This single habit — treating your outdoor clothing once per season — is the highest-impact personal tick prevention measure available. More effective than DEET alone. The CDC recommends it for outdoor workers, hikers, and anyone in tick-endemic areas.
Pants, socks, shoes, shirts, hats, and gear (backpacks, tents, sleeping bags). Focus especially on socks and lower pant legs where ticks typically first contact clothing. Treat the exterior surface — not the skin-contact side.
Permethrin vs. bifenthrin for yard spray — when to use which
For yard tick control, apply permethrin to the lawn-woodland edge (the 9-foot transition zone between maintained grass and wooded areas) in late April and late August. Also treat along fence lines, under decks, and in tall grass areas. Do not apply to flowering plants.
Permethrin products — consumer and professional
| Product | Concentration | Use |
|---|---|---|
| Sawyer Permethrin Spray | 0.5% | Clothing and gear treatment — #1 choice |
| Martin's Permethrin 10% | 10% concentrate | Dilute for yard spray — economical |
| Bonide Mosquito Beater | 0.1% RTU | Ready-to-use yard spray |
| Permanone (aerosol) | 0.5% | Military/outdoor clothing treatment standard |
| Gordon's Permethrin 10% | 10% concentrate | Livestock, dogs, yard — versatile concentrate |
Critical safety information
Permethrin is acutely toxic to cats when wet. Cats lack the liver enzyme (glucuronyl transferase) that metabolizes pyrethroids. Exposure to wet permethrin — even from treated clothing that isn't fully dry — can cause tremors, seizures, and death in cats. Always: treat clothing outdoors, dry completely before bringing inside, and keep cats away from any treated surfaces until fully dry. Dried permethrin on clothing is safe around cats.
Like all pyrethroids, permethrin is highly toxic to fish and aquatic invertebrates. Never apply within 50 feet of water. Do not apply before rain. The aquatic toxicity risk is the primary environmental concern with permethrin yard applications.
Permethrin poses very low toxicity risk to dogs and humans when dry. The EPA classifies it as likely not carcinogenic to humans. The clothing treatment use is considered one of the safest pesticide applications available — the amount absorbed through treated fabric is far below any health threshold.