Debunk
Do mosquito gadgets work?Do mosquito gadgets actually work?
Ultrasonic devices, bug zappers, repellent bracelets, and kids' stickers are everywhere. Here is what controlled studies and regulators actually found.
Updated July 22, 2026 · Reviewed against our scoring methodology
Every spring the same gadgets flood the shelves: little ultrasonic boxes that promise a silent force field, wristbands and stickers that say they protect a child all day, and blue-glowing zappers that crackle on the patio. They sell because they are cheap, chemical-free, and easy to believe in. The problem is that when scientists test them against real mosquitoes and real skin, they do not work.
We list them here, with the evidence, so you can skip them and spend on what protects you instead.
The short version
Ultrasonic devices & phone apps
Does not work
A Cochrane review of ten field studies found no effect on biting. Mosquitoes do not flee ultrasound.
Repellent wristbands & bracelets
Does not work
Repellent vapor only protects within a few centimeters of the source, so a band on the wrist leaves the rest of you exposed.
Repellent stickers & patches
Does not work
Same problem as bands: a patch on a shirt cannot protect arms, legs, and face.
Bug zappers (for bites)
Does not work
They kill thousands of insects, but almost none are biting mosquitoes; mostly harmless and beneficial bugs.
Ultrasonic devices and apps
The idea is that a high-pitched sound drives mosquitoes off. It does not. A Cochrane systematic review pooled ten field studies and found no difference in biting whether the device was on or off, and concluded there is no justification for marketing them. The US Federal Trade Commission has brought enforcement actions against companies for selling ultrasonic repellers on unsupported claims. Phone apps are the same physics with a worse speaker.
Bracelets, bands, and stickers (including the kids' ones)
The oils in these bands are not the problem; the format is. A repellent works by holding a vapor barrier right at your skin, and that barrier reaches only a few centimeters. A band on one wrist, or a sticker on a shirt, cannot cover two arms, two legs, and a face. In the gold-standard comparison trial (Fradin and Day, New England Journal of Medicine), wristbands gave essentially no protection while a spray on the skin protected for hours. That is why we score every band and sticker, including the ones marketed for children, as not recommended.
Kids deserve the real thing
A sticker on a toddler's shirt is not protection. Health agencies say picaridin and lemon-eucalyptus (OLE, for ages 3+) or a low-concentration DEET are safe, effective options for children when used as labeled. A band is not.
Bug zappers
Zappers do kill insects, so it feels like they are working. But in a classic study of suburban zappers, of the nearly 14,000 insects they killed only 31 were biting flies. About half were harmless insects that fish and birds rely on for food, and many of the rest were predators that help keep other pests down. A zapper thins the good bugs and barely touches the ones biting you. (CO2-baited traps are a different, better-supported technology.)
What to use instead
On your skin: an EPA-registered repellent (DEET, picaridin, IR3535, or OLE). For a patio: a Thermacell-type spatial device. For standing water you cannot drain: a Bti dunk. Those are the tools with evidence behind them.
Common questions
- Do ultrasonic mosquito repellents work?
- No. A Cochrane review of ten field studies found ultrasonic devices have no effect on mosquito biting, and the FTC has fined marketers for unsupported claims. Phone apps that play the same sounds do not work either.
- Do mosquito repellent bracelets work for kids?
- No. The band format cannot protect the whole body, because repellent vapor only works within a few centimeters of the source. A wristband leaves a child's arms, legs, and face exposed. For children, use a picaridin or lemon-eucalyptus (age 3+) repellent on exposed skin instead.
- Do bug zappers keep mosquitoes away?
- No. Zappers kill mostly harmless and beneficial insects; studies find biting flies are a tiny fraction of the catch. They do not reduce how much you get bitten.
- Are repellent stickers safe and effective for kids?
- The stickers are generally non-toxic, but they do not protect against bites: a patch on clothing cannot cover the whole body. Safe is not the same as effective.