Keep It In The Fight
A trap is only a weapon while it's supplied and maintained. The ammunition is Bti — and it's the one thing you have to buy.
Ammunition Brief — Bti
What "Bti" actually means (it's what's in every dunk)
Bti stands for Bacillus thuringiensis subspecies israelensis — a naturally occurring soil bacterium. When mosquito larvae eat it, proteins in the bacteria destroy their gut and they die within a day or two. It targets only the larvae of mosquitoes, black flies, and fungus gnats — and is harmless to people, pets, fish, birds, bees, and plants. It's approved for organic gardening. This isn't a poison you're spraying around; it's a targeted biological control.
It comes in two forms — most places want both:
Dunks
Beige floating "donuts." Slow-release — one treats up to ~100 sq ft and lasts 30+ days. Your long-haul ammo. Break into pieces for small containers.
Bits
Granules you sprinkle on. Fast knockdown within 24 hrs, but only lasts ~1–2 weeks. Crash a water that's already crawling, then drop a dunk for the hold.
Known good brand: Summit — "Mosquito Dunks" and "Mosquito Bits," sold just about everywhere. Unused dunks keep their potency indefinitely, so stock up. Always follow the product label — it's the law and it's the dose.
Where to Resupply
SUPPLY LINE — WHERE TO RESUPPLY
About $10 for a 6-pack of dunks, or a similar price for a shaker of Bits. Most stores carry both — grab dunks for the long hold and a tub of Bits for fast knockdowns. Buy local if you can — here's where to find them:
Maintenance Tempo
Weekly — Top Off
Add water if it's dropped. A dry trap is combat-ineffective — and a half-dry one still breeds.
~Monthly — Re-Dunk
Dunks dissolve over about 30 days. Drop a fresh one in before the old one's gone.
⚠ WARNING — A NEGLECTED TRAP DEFECTS
An abandoned trap doesn't go quiet — it switches sides. Still water with no Bti is exactly what the enemy wanted. If you can't keep it up, dump it out and flip it over. An empty bucket beats a forgotten one.