UK heatwave fuels rat surge, experts advise cheap pepper spray DIY repellent

A prolonged heatwave across the United Kingdom has triggered a sharp increase in rat activity, extending the breeding season and leading to more frequent infestations in homes, garages and basements. Rats, which thrive in warmer conditions, are spreading disease and causing damage, prompting homeowners to seek low‑cost deterrents.

The Express reports that a simple mixture of cayenne pepper – available for about £1 at supermarkets such as Asda – mixed with water and a drop of washing‑up liquid can be boiled and cooled to create an effective, non‑lethal repellent that irritates rats' sensitive noses and drives them away.

Pest‑control experts, including Professor Steven Belmain of the University of Greenwich, warn that “humane” live traps are largely ineffective and can cause additional stress to captured animals. Belmain advises that the most welfare‑friendly approach is to eliminate food sources and improve sanitation, while acknowledging that poisons and kill‑traps remain the primary control methods. Research into rodent contraception is ongoing, but immediate action focuses on sanitation and, where appropriate, rapid‑kill devices.