Ultrasonic mosquito repellents are small, battery-operated devices marketed as a popular non-chemical option for deterring biting insects. These products emit high-frequency sound waves, typically above 20 kilohertz (kHz), which is beyond the range of human hearing. Marketed as a convenient, hands-free solution, the core premise is that a silent, invisible shield of sound can keep mosquitoes away. Do these high-frequency sound waves actually function as an effective deterrent?
The Claimed Mechanism of Repulsion
Manufacturers base their marketing on two primary behavioral theories to explain why the ultrasonic sound should repel mosquitoes. The first theory suggests the high-pitched frequency mimics the sound of a male mosquito’s wing beat. Since only the female mosquito bites, the sound is supposedly meant to repel mated females who are trying to avoid further encounters with males. The second claim is that the sound waves imitate the wing beat or echolocation frequencies of natural mosquito predators, such as dragonflies or bats. This sonic threat is theorized to create an environment that mosquitoes perceive as dangerous, causing them to flee the area of the device.
Scientific Consensus on Efficacy
Despite the compelling marketing claims, numerous scientific studies and public health organizations have consistently concluded that ultrasonic mosquito repellents are ineffective. Research conducted in controlled laboratory and field settings has found that the devices fail to reduce mosquito landings or biting rates. In some instances, the sound emissions have even been observed to slightly increase mosquito attraction to the wearer.
The devices fail because the actual auditory sensitivity of most mosquito species is far outside the ultrasonic range. Many species hear best in the range of 100 to 500 Hertz (Hz). This lack of scientific proof has led the Centers for Disease Control and Prevention (CDC) to state explicitly that ultrasonic devices do not prevent mosquito bites.
The Federal Trade Commission (FTC) has taken action against manufacturers for making these unsubstantiated claims, sending warning letters to more than 60 companies. The FTC requires that claims regarding the devices’ effectiveness must be supported by competent and reliable scientific evidence. This regulatory enforcement reinforces the scientific consensus that ultrasonic products are not a reliable method for personal mosquito protection.
Reliable Alternatives for Mosquito Control
Since ultrasonic devices do not provide adequate protection, proven methods should be used to minimize exposure to biting mosquitoes. Chemical repellents that are registered with the Environmental Protection Agency (EPA) remain the most effective option for personal use. Repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus (OLE) have demonstrated strong efficacy in field tests.
Products with DEET concentrations between 7% and 30% or Picaridin concentrations of 10% to 20% offer dependable protection. Oil of Lemon Eucalyptus, or its synthetic derivative PMD, is another effective choice, requiring a concentration of 30% to 40% for optimal results. Non-chemical strategies include treating clothing and gear with Permethrin, a contact insecticide. It is also highly effective to eliminate all sources of standing water around the home, as these are the necessary breeding sites for mosquitoes.