How does it work as a pest repeller? 
This unit uses ultrasonic technology to repel pests from your yard as well as sonic alarm/harassment noise and strobe lights. 
Briefly, 3 pest repelling technologies:  
- Strobe light with sun down sensor creats continuous intimidating flashes that confuse and frighten pests away.  
- Inaudible to humans, the high pressure ultrasonic has an adjustable dial to target different pests.  
- Audible predator alarm sounds like a terrifying hawk and is especially effective on birds and rodents (Alarm can be turned off or set to low volume to avoid disturbing neighbours in residential areas).  

How does it work as a bird control device?
It is a low profile bird control device that uses ultrasonic sound waves (silent to most humans, high-pitched and irritating to birds) to force away unwanted pest birds & small animals. The emitted sounds annoy pest birds & drives them away to areas that are more calm & untreated. Both motion-activated and continuous operation modes allow for easy operation & minimal maintenance. Works to deter pigeons, crows, blackbirds, sparrows, starlings, swallows, grackles, ducks, seagulls and gulls, rodents, bats, & more. Please allow 2 to 3 weeks to see the full effect of the unit; behavior modification can take time.

Placement:
It’s important to place the device where it will be most effective. For ground animals, like raccoon, coyotes, etc. Place the unit near the height of the animal you want to repel and facing the area where they most like to frequent. Don’t place it on the ground as this will limit the effective range of the device.

Note: Blankets, clothing, or other soft items will absorb ultrasonic waves. Do not place these items in front of the ultrasonic horn