Go Green with the Ultrasonic Rodent Repeller which is specifically designed to humanely repel rats & mice. Mice and rats are the most common indoor rodent pest problem encountered by consumers worldwide. SAVE with this 3 pack of Single Speaker Rodent Repellers. Non-toxic ultrasonic rodent repellers are specifically designed to repel rats & mice, the most common indoor rodent pest problem encountered by consumers worldwide. Rats and mice pose serious health risks, and traps and poisons come with a heavy price. Poisons can endanger children and pets while inhumane traps require the handling of potentially disease-bearing rodents. Neither poisons nor traps provide long-term protection since more rodents will likely replace the ones you've killed. It can be an unending cycle. Ultrasonic or Electronic Rodent Repeller puts the emphasis on non-toxic prevention, instead of after-the-fact toxic intervention. Ultrasonic rodent repellers emit high frequency ultrasound waves between 32 and 62 kHz to create an acoustically hostile environment that repels rodents from sound-protected areas, over the long term. Ultrasound is kinder than traps, safer than poisons, and inaudible to people and non-rodent pets. The physical properties of ultrasonic sound prevent ultrasonic sound waves from penetrating solid objects like walls and floors. Therefore it is recommended to place one rodent repeller in each room of the location being treated for rodents. Ultrasonic waves are highly directional and will bounce off of hard surfaces to fill an enclosed area with high intensity echoes. Hard surfaces are cement, brick, glass, tile, etc. On the other hand, ultrasound is absorbed and dampened by soft surfaces, such as hay bales, feed sacks, stacked linens, etc. Go Green and Make an Impact!