Bell and Howell ultrasonic pest repellers are among the most widely sold plug-in pest devices on the market, but the evidence strongly suggests they don’t work. Despite thousands of consumer ratings on retail sites, scientific testing and federal regulators have repeatedly found that ultrasonic pest repellers fail to deliver on their core promise: driving rodents and insects out of your home.
What Bell and Howell Claims
The company markets several models, with the most popular being a six-pack kit sold at major retailers like Home Depot. Each unit plugs into a standard outlet and claims to cover up to 120 square feet using “variable ultrasonic frequencies” that are inaudible to humans and pets but irritating enough to drive rodents and insects away. The variable frequency feature supposedly prevents pests from getting used to the sound over time. At roughly $20 to $30 for a multi-pack, the price point is low enough that many people figure it’s worth a try.
What the Science Actually Shows
Independent scientific evaluations have consistently found no measurable effect from ultrasonic devices on the pests they claim to repel. Cornell University’s Integrated Pest Management program reviewed the evidence and was blunt: scientific evaluations found no effect on German cockroaches, bed bugs, or rodents. That covers the most common household pests these devices are sold to address.
The “variable frequency” claim deserves special attention. Even the FTC has noted that any initial reaction rodents have to ultrasound is temporary at best. Mice and rats become accustomed to the sound and return to their nesting and feeding areas even with a device running. Insects, meanwhile, show no meaningful response to ultrasound at all.
So why do some buyers leave glowing reviews? Cornell’s pest management experts point to a simple explanation: people who don’t see mice after plugging in a repeller may never have had a serious mouse problem to begin with. A well-sealed home with no accessible food or water won’t attract rodents regardless of whether an ultrasonic device is running. The repeller gets credit for something it didn’t do.
The FTC Has Warned This Entire Industry
The Federal Trade Commission has been scrutinizing ultrasonic pest repeller claims since the mid-1980s. Between 1985 and 1997, the agency brought enforcement actions against six companies for making false and unsubstantiated claims about ultrasonic pest control. Every case was resolved with a consent order, meaning the companies agreed to stop making those claims.
In 2001, the FTC sent warning letters to more than 60 manufacturers and retailers of ultrasonic pest devices, stating that all efficacy claims must be supported by scientific evidence. The specific claims the FTC challenged included that these devices eliminate rodent infestations, repel insects, serve as an effective alternative to conventional pest control, and that scientific tests prove product effectiveness. Bell and Howell’s marketing language hits several of these same themes.
A Potential Problem for Pets
Bell and Howell states their devices are safe for pets, but the frequency ranges raise questions. Many ultrasonic repellers, including models in this category, operate in the 25 to 65 kHz range. Cats can hear frequencies up to roughly 65 kHz, which means these devices may be producing sounds that fall squarely within your cat’s hearing range. Dogs hear up to about 45 kHz, so they could also be affected by the lower end of these frequencies. Whether this causes discomfort or stress is difficult to measure, but it’s worth knowing that “inaudible to pets” may not be entirely accurate, particularly for cats.
What Actually Works for Indoor Pests
The CDC recommends an approach called integrated pest management, which boils down to three steps: don’t attract pests, keep them out, and eliminate them with the safest effective methods if they’re already inside. That sounds simple, but the details matter.
Start with inspection. Walk through your home looking for entry points, particularly gaps around pipes, doors, and foundation cracks. Mice can squeeze through openings the size of a dime. Seal those gaps with steel wool, caulk, or metal flashing. Next, remove what pests need to survive: accessible food, standing water, and sheltered nesting spots. Store dry goods in sealed containers, fix leaky pipes, and clear clutter from storage areas.
If you already have an active infestation, identification matters. The right approach for roof rats differs from Norway rats, and what works on ants won’t work on cockroaches. Snap traps remain one of the most effective and affordable tools for rodents. For insects, targeted baits tend to outperform broad-spectrum sprays because they reach the colony rather than just the individuals you can see. If an infestation persists after your own efforts, a licensed pest control professional can identify the species and apply targeted treatments.
The key difference between these methods and an ultrasonic plug-in is that integrated pest management addresses why pests are in your home. A device that claims to annoy them into leaving, even if it worked, wouldn’t solve the underlying conditions that attracted them.