Multi-packs: Ultrasonic pest repellers often come in multi-packs, allowing you to place several around your house. This makes them cost-effective. For example, the Desirez2Door Ultrasonic Pest Repeller comes in a six-pack, and each one can cover an area of 2000 square feet.

Installation: The indoor repellers are the easiest to install--you just have to find a strategic location where you have a pest infestation and plug them in. If you need a pest repellant for a car or boat, it might have a more challenging installation process. Consult the instruction manual to make sure you install them properly.

Frequency: The devices have varying levels of ultrasonic waves that they emit. Repellers with higher frequencies will less likely harm other animals in your homes except for the insects and rodents that they’re meant to target. Repellers with lower frequencies are recommended for outdoor purposes, as they can hurt your house pets and other animals. Many repellers will convert the frequency of their signal from time to time so that pests won’t become accustomed to the sound. That’s a desirable feature, as in the FitFort Pest Repeller.

Range: The common ultrasonic pest repellers are powerful enough to cover 1200 sq. ft. Some pest repellers are more powerful and can cover up to 5000 sq. ft. The choice you go for is dependent on the size of the infested area.

Night light: Some repellers have an indicator light to let you know that they are working. Some of these indicators can also serve as a night light, especially in the case of outdoor pest repellers.

MaxMoxie Ultrasonic Pest Repeller is easy to use, and it is safe around kids and pests. It comes in a pack of two repellers. They are effective for deterring rodents, roaches, spiders, bed bugs, mosquitoes, and ants. It has a nightlight feature that produces a soft glow in the dark. The repeller has a frequency of 20 kHz to 60 kHz and has a range of 1200 sq. ft. The repeller can last for five to six years.

Bell + Howell Ultrasonic Pest Repeller is a pack containing six devices, in three different sizes. The smaller-sized devices are so that you can place them in hard-to-reach places. The medium sizes are suitable for hallways and basements, and the large-sized devices are appropriate for the rooms. It is effective against ants, cockroaches, spiders, and rats. It is easy to install and affordable.

WahooArt makes a corded ultrasonic pest repeller that can cover a range of 2000 sq. ft. A single device comes with four emitters making it suitable to cover a home. It takes two weeks of use to start seeing results.