Revolutionary Rat Repellent Developed by Swedish Researchers

Researchers at Luleå University of Technology (LTU) and the Swedish University of Agricultural Sciences (SLU) have unveiled a groundbreaking rat repellent known as Repello, designed to send rodents fleeing in fear. This patented Swedish innovation emits sounds that target the rodent's reptilian brain, effectively mimicking the warning signals they make when they grind their teeth. According to Örjan Johansson, a professor of technical acoustics at LTU, the device emits frequencies that are particularly sensitive to rats, amplifying sounds that they inherently recognize as threats. The system employs complex sound sequences rather than relying on a single, monotonous tone, a feature that has historically rendered simpler ultrasonic devices ineffective. When used continuously, these prior devices allowed rodents to acclimate and return despite the presence of sound deterrents. Repello stands out by utilizing varied patterns in frequency and intensity that prevent the rats from becoming accustomed to the signals. Johansson likens this to the effective technology behind military sound cannons, where unpredictability keeps the target's brain on high alert, simulating an acute life-threatening situation. This innovative approach ensures that rats perceive the noise as an imminent danger, prompting them to flee immediately. The efficacy of Repello has been confirmed through field tests conducted in Gothenburg. In one notable property, the number of observed rats dramatically decreased from 44 to zero within days—none of which returned, despite the availability of food and shelter. This remarkable outcome highlights the effectiveness of the complex sound patterns and addresses a persistent issue: rodents typically learn to ignore monotonous ultrasound frequencies, even those at intense decibel levels. With growing international interest, Repello has garnered attention in Sweden, being featured by major media outlets such as SVT and TV4. As of now, this advanced sound repellent is available on the market, with each unit capable of covering up to 40 square meters. Related Sources: • Source 1 • Source 2