Do ultrasonic pest repellers actually work?

Key points

• Ultrasonic pest repellers emit high-frequency sounds to deter pests such as roaches and rats.

• Studies have found a lack of evidence that ultrasonic pest repellers control household pests.

• Tried and true pest control methods — applying pesticides, setting traps and sealing entry points — are more reliable.

Ultrasonic pest repellers use high-frequency sound outside the range of human hearing to repel rats, mice, cockroaches, termites, fleas, bedbugs and other pests. Some companies even claim that their devices get rid of all types of insects and pests. But whether these devices are effective is a cause for some debate.

According to several studies that tested the effectiveness of these products, ultrasonic pest repellers do little to discourage pests from entering or taking up residence in and around your home.

In 2001, the Federal Trade Commission sent warning letters to over 60 ultrasonic pest repeller manufacturers because the companies’ advertising made claims that weren’t supported by scientific evidence. In the following years, the FTC brought complaints against other companies who claimed, without scientific evidence, that their products effectively repelled pests.

Beau Montoya, pest control expert and owner of 911 Pest Pro Solutions in Las Vegas, said that in his almost 20 years in the field, he has never seen ultrasonic repellers produce the results they claim. “I have been to thousands of customers, and I can count on one hand how many [clients] I have seen own these,” he said.

Despite the lack of evidence, ultrasonic pest repellers on the market still claim to be an effective pest control method. Here’s everything you need to know about these devices.

How do ultrasonic pest repellers claim to work?

Ultrasonic pest repellers claim to work by emitting high-frequency sounds above the range of what human ears can detect. Sounds detectable by humans fall between 20 Hz (hertz) to 20 kHz (kilohertz). Sounds above this range are detectable by other mammals, rodents and arthropods, including insects, spiders and mites.

According to ultrasonic pest repeller manufacturers, these sounds discourage pests from coming into close proximity to the devices. But because the sound doesn’t travel well through walls, multiple units are necessary to control pests throughout the entire home and outdoor area.

Insects, rodents and other pests are notoriously difficult to control, so a plug-in or battery-operated ultrasonic pest repeller seems like an easy solution. In reality, you may just be taking up an outlet or using up batteries with no real results.

What pests do ultrasonic repellers target?

Manufacturers of ultrasonic repellent devices claim that these products target a wide range of rodents and insects, but won’t affect people or pets. They claim that pests deterred by ultrasonic sounds include the following:

• Rats
• Bed bugs
• Fleas
• Mice
• Termites
• Spiders
• Mosquitoes
• Flies

“Ultrasonic pest repellers are marketed to target a variety of pests, but their effectiveness varies across different pests and environments,” said Jana McDaniel, creator of eco-friendly insect repellent First Saturday Lime.

Are ultrasonic pest repellers effective?

While manufacturers of ultrasonic pest control devices claim they are effective against a variety of tiny home invaders, the science says differently. “Commercially available sonic pest devices for use in residential applications have not been shown to be effective in scientific studies,” according to a 2015 paper published by the University of Arizona College of Agriculture & Life Sciences extension.

Since the 1960s, scientists have studied the effects of sounds on rodents, insects and other pests with little results. Studies commonly place a certain number of target rodents or insects in each of two chambers, both fitted with an escape tube. One chamber includes an ultrasonic device while the other includes a control device that emits no sound.

Some studies of ultrasonic devices have shown limited results, but most have observed that while some test subjects may show a mild aversion at first, they often become accustomed to the sound.

In a 1969 study published in The Journal of Wildlife Management that tested ultrasonic device effectiveness in rats and mice, the test subjects initially showed an aversion, but then, “rather than starve or go thirsty, both rats and mice would venture into the room with ultrasound to reach known sources of food and water.” Even if food was available elsewhere, some of them would continue to get food and water from the room with the ultrasonic device.

One notable result was reported in a 2010 study published in the Journal of Vector Ecology that compared three commercial sonic devices that claimed to repel mosquitoes. The study showed that the devices actually attracted mosquitoes and resulted in a 50% bite-rate increase.  Other studies, including the one conducted at the University of Arizona, showed that ultrasonic devices had no effect on bed bugs, ants or cockroaches.

While some of these studies, such as the one studying rats and mice, were done over long time periods — either 76 or 81 days in this case — other studies tested the reactions over a much shorter period.

In the study that tested mosquitoes, the test ran for four cycles of three minutes each. Some ultrasonic pest repellers claim that it takes two to four weeks to rid the home of pests, so the study’s unpromising results could potentially be due to the test’s short duration. However, given the number of studies that lack results proving the effectiveness of the devices, it’s likely that they don’t work as they claim to.

Which ultrasonic pest repellers work best?

Several ultrasonic pest repellers on the market claim to work as effective pest control options, but scientific studies have shown that they don’t affect household pests. Montoya backed this up: “Being in this industry as long as I have and having to read and study to stay updated on different insects and characteristics and what truly eliminates them, not one time have I read that sounds will destroy them,” he said.

Are ultrasonic pest repellers safe for pets and humans?

Ultrasonic pest repellers claim to be safe for humans and pets even though the high frequency is detectable by household pets, such as cats and dogs, and other common pets, including guinea pigs and possibly even hamsters.

McDaniel said, “When used properly, most ultrasonic pest repellers are considered safe for humans and pets since the high-frequency sounds are above our audible range.” When it comes to pets, she said, “Some pets, like dogs, may potentially hear the ultrasonic pitches, which could cause distress or discomfort over prolonged exposure.”

Montoya, however, said, “There has been no proof that it has any effect on pets. The sound isn’t strong enough for them to have any real care.” If you use ultrasonic pest repellers around your pets, pay attention to any changes in their behavior to determine if the device is negatively affecting them.

“For humans, there have been some side effects,” said Montoya. In a 2018 study published in The Journal of the Acoustical Society of America on the possible adverse effects of ultrasonic devices on humans, researchers determined that “perceptual evaluation showed that 20-minute exposure to the investigated device settings did not lead to hearing damage nor to significant undesirable effects such as headache, tinnitus, nausea in the two different age groups.”

Despite their overall finding, a few people in the study did report that the sounds in the 25–28 kHz signal were disturbing. The study was careful to point out that the participants may not struggle with hearing sensitivity, and people should still use caution as higher frequencies may produce adverse effects in people who do show hearing sensitivity. 

What are better alternatives to ultrasonic pest repellers?

If you’re looking for a better alternative to ultrasonic pest repellers, Montoya recommended the following: “Stick with a pesticide or hire a pest control company that has the knowledge to take care of your problems quickly and efficiently rather than hoping something works.”

The best pest control methods will depend on the type of pest. Your approach will be different, whether you’re trying to get rid of mice in the walls or ward off German cockroaches. The infestation level will also demand varying levels of effort. Still, some tried and true pest control methods include chemical pesticides and sprays, sealing up entry points, and trapping and releasing.

What’s next?

Ultrasonic pest repellers aren’t an effective way to deter pests. If you start seeing signs of an infestation around your home, it’s best to contact a pest control service in your area that specializes in the type of pest you’re seeing. Some companies deal with many different types of pests while others may specialize in rodents, roaches, termites or other common household pests.

Many companies offer free inspections to evaluate the extent of the infestation and determine the best course of action. You can also purchase pest control sprays and traps from a local hardware store or even from Amazon. Still, without professional knowledge, DIY methods may not be as effective as professional insect and rodent control solutions.