Set traps close to walls, behind objects, in dark corners and in places where rat signs or activity are observed. Place traps so rats will pass directly over the trigger when following their natural course of travel. Use enough traps to make the effort short and decisive. To Traps Alternative to traps are glue boards, which catch and hold rats attempting to cross them in much the same way flypaper catches flies. Place Glue boards along walls or in other areas where rats travel.
Rats quickly become accustomed to regularly repeated sounds.
Ultrasonic sounds, those above the range of human hearing, have very limited use because they are directional and do not penetrate behind objects. They also lose their intensity quickly with distance. There is little evidence that electronic, sound, magnetic, or vibration devices of any kind will drive established rats from buildings or provide adequate control. The presence of garbage and other refuse allows rats to exist in residential areas. Good sanitation will not eliminate rats under all conditions, but will make the environment less suitable for them to thrive.