- Location, Location, Location
First, identify a room that has signs of rodent activity. Rodents are nocturnal creatures, which mean they rarely surface during the daytime. Look for the signs of an infestation: chewing or gnaw marks, droppings, tracks and nests. Next, plug the unit into an outlet which is open to the rest of the room, not behind furniture where the sound waves may be blocked. Ultrasound is reflected by hard surfaces and absorbed by soft surfaces. In a room with mostly hard surfaces, like a kitchen, ultrasound will "bounce" around giving more effective coverage. The ideal placement would be one that allows the sound waves to cross in front of an entranceway.
- Use Multiple Units
Ultrasonic waves behave more like light than sound. For example, music from your stereo can fill your entire house. Ultrasound cannot penetrate any solid surface (walls, floors, ceilings) or travel around corners. This is why you need a unit for each room. The rule regarding square footage coverage is simple: an ultrasonic device can only cover the room in which it is installed; in a 10' x 10' room it covers 100 sq ft, in a double car garage it covers 400 sq ft. With obstructions, you will need to install more than one unit for maximum effectiveness.
- Monitor Rodent Activity
Monitoring the signs of rodent activity will allow you to correctly place the units in high-frequency areas and allow you to direct the unit towards their entry points. Additionally, regularly checks for the signs of recent rodent activity (fresh droppings, rodent noises, new gnaw damage) will allow you to confirm the population is dissipating. Remember, rodent populations can tolerate unfriendly changes in their environment for only a short time so you can expect to see a reduction in activity after 6 to 10 days on average.
- Use In Conjunction With Other Controls For Established
Ultrasonic devices should not be used alone to control an established infestation. Traps and rodenticides as well as sanitation and exclusion efforts should be used in conjunction with ultrasonic repellents. In fact, ultrasonics can be used as a herding tool to force rodents into areas equipped with traps and baits.