Do ultrasonic mosquito repellers work?
Quick answer
No — ultrasonic mosquito repellers don’t work. A Cochrane review of 10 field trials found no measurable effect on biting or on mosquito landing rates. Apps, wristbands, and plug-in devices that claim to drive mosquitoes off with sound have failed every controlled test.
Why it doesn't work
Electronic mosquito repellers claim to emit ultrasound that either mimics a dragonfly (a predator) or a male mosquito's wingbeat (to repel gravid females). Both premises are biologically unsound. Female mosquitoes do not flee from a generalized ultrasonic tone, and the "they avoid males/predators by sound" story does not survive testing — mosquito hearing is tuned to the low-frequency wingbeat of conspecifics at close range for mating, not to broadband ultrasound used as a deterrent at distance.
This is one of the few backyard-gadget questions with a systematic review behind it. Enayati, Hemingway & Garner’s Cochrane review pooled the field trials of electronic mosquito repellers and concluded there is no evidence they prevent mosquito bites, and that they have "no role" in protecting against bites or malaria. Independent landing-rate and biting-rate studies of commercial ultrasonic devices repeatedly find no reduction versus control.
The mechanism failure explains the trial failure. Host-seeking is driven by chemosensation and thermosensation — CO₂, lactic acid and other skin odors, heat, and humidity — detected by antennal and maxillary-palp receptors. A loudspeaker emitting ultrasound provides no input to that pathway and provides no reason for a hungry female to abort an approach she is making on a CO₂ plume. Smartphone "anti-mosquito" apps are worse still: most phone speakers cannot even reproduce the claimed frequencies at a meaningful amplitude.
This category is worth singling out because it is sold with confident specificity ("repels via 22 kHz dragonfly frequency") that sounds scientific and is not. The honest, evidence-based tools remain the unglamorous ones: skin-applied EPA-registered repellents, source reduction of standing water, and — for area suppression — emitting the cues mosquitoes actually follow and trapping them.
References
- Enayati, A.A., Hemingway, J. & Garner, P. (2007), "Electronic mosquito repellents for preventing mosquito bites and malaria infection," Cochrane Database of Systematic Reviews 2007(2):CD005434.
- Andrade, C.F.S. & Cabrini, I. (various), field tests of ultrasonic devices showing no effect.link pending verification
What to do instead
The honest answer isn't "give up" — it's to target the host-seeking females directly. A CO₂ + heat trap broadcasts the breath-and-body cues mosquitoes actually follow, drawing them away from you and capturing them, without spraying pesticide across your yard.
See the SkeeterSwitch bundleCommon questions
Do ultrasonic mosquito repellers work?
No. A Cochrane systematic review of field trials found no evidence they reduce mosquito bites.
Do anti-mosquito phone apps work?
No. The premise is unsupported and most phone speakers can't even produce the claimed frequencies effectively.
Why doesn't sound deter mosquitoes?
Host-seeking is driven by smell (CO₂, skin odor) and heat, not hearing. An ultrasonic tone gives a hungry female no reason to turn back.
What about devices that mimic a dragonfly?
Mosquitoes don't avoid a broadband ultrasonic tone, and the trials of these devices show no protective effect.