I dealt with a bat colony in my attic for two summers, and ultrasonic repellers were one of the tools that helped me regain that space. They are not magic, and they will never replace sealing the entry points, but combined with proper exclusion they made a real difference. These are the five I would buy again.
| Repeller | Coverage | Power Source | Best For |
|---|---|---|---|
| Bell+Howell Ultrasonic | 1500 sq ft | Plug-in | Attics |
| Neatmaster Dual Speaker | 1200 sq ft | Plug-in | Garages |
| Cravegreens Pest Control | 1000 sq ft | Plug-in | Sheds |
| TBI Pro Solar | Outdoor | Solar | Patio edges |
| Loraffe Under Hood | 1 vehicle | 9V battery | Cars and RVs |
Bell+Howell Ultrasonic
The Bell+Howell is the device I started with and the one I still recommend for attic and crawlspace use. It plugs into a standard outlet, emits a sweep across the 25 to 65 kHz range that bats hear well, and has a soft night light that you can disable. Coverage is generous for a single device in a finished attic. Pair two of them at opposite ends for full coverage.
Neatmaster Dual Speaker
The Neatmaster has two front speakers and an LED-flash mode that some users find helpful for nocturnal pests. The dual-speaker design covers a wider arc than single-driver units. I used one in a detached garage where I was finding bat guano and within three weeks the activity dropped to near zero.
Cravegreens Pest Control
A more compact plug-in design with a quieter draw, the Cravegreens is the one I use in my potting shed and tool shed. Smaller coverage but cheap enough to buy in a four-pack. The build is plastic but they have held up to dust and temperature swings for two seasons now.
TBI Pro Solar
For exterior use, especially along porch eaves where bats sometimes gather, the TBI Pro Solar is the unit I compared. It charges off a small solar panel during the day and emits ultrasonic sweeps and motion-triggered LED flashes at night. Outdoor effect is more limited than indoor, but it discourages roosting along the edges of the house.
Loraffe Under Hood
A niche pick but useful for RVs and vehicles stored outdoors where bats sometimes roost in the engine bay. The Loraffe runs off a 9V battery, mounts with zip ties, and emits a sweep that discourages both rodents and bats. I installed one in my pickup after finding a guano problem.
What Matters Most
Ultrasonic repellers work best in enclosed spaces where the sound waves bounce off hard surfaces and cover the room. In open air the effect drops quickly. They are also a deterrent, not an evicting tool, which means you cannot count on them to drive out an established colony. The proper sequence is identify entry points, install one-way exclusion devices, then run ultrasonic devices to discourage return.
My Setup
I have two Bell+Howell units in my attic running 24/7, a Neatmaster in the garage, and Cravegreens units in both sheds. Total power draw is minimal, around 20 watts combined.
Common Mistakes
The biggest mistake is treating ultrasonic devices as a complete solution. Bats are protected wildlife in many areas, exclusion has legal restrictions, and the only permanent fix is sealing the building. The second mistake is plugging the device in a position where furniture or insulation blocks the speaker.
Final Recommendation
For attic use the Bell+Howell is the right starting point. Garages get the Neatmaster. Sheds and outbuildings work well with multipack Cravegreens. Patios add the TBI Pro Solar. Vehicles use the Loraffe.
Frequently asked questions
Do ultrasonic bat repellers actually work?+
They can reduce bat activity in enclosed spaces like attics, sheds, and garages where the sound bounces around. In open air patios the effect is much weaker. They are never a substitute for sealing entry points.
Are these devices safe for pets?+
Generally yes for cats and dogs, who hear higher frequencies but tend to ignore the steady tone. Rabbits, hamsters, and rodents may be stressed, so keep the devices out of their rooms.