Bedbug infestations are soaring in the UK as the critters become increasingly resistant to the chemicals used to kill them, data reveals. One London borough alone has had to tackle 40% more bedbug infestations this year compared to the same period in 2025.
Rising Infestations Across the UK
Pest controllers report being flooded with cases, and the parasites are now resistant to most major insecticides. The cost-of-living crisis has also driven more people to ineffective DIY treatments, causing infestations to spread out of control. Bedbugs are small insects that feed on human blood and typically shelter in mattresses, bed frames, or cracks near sleeping areas.
Data gathered from across the pest industry reveals a spike in bedbug infestations in 2026. One London borough—which agreed not to be named—has already dealt with 155 infestations in the first half of this year. That number is 40% higher than in the first six months of 2024 and 50% larger than the same period in 2024. The 52 infestations the council handled in June 2026 is their largest monthly total since before the Covid pandemic.
Resistance to Insecticides
The bedbug spike is not isolated to London. James Rhoades, whose company ThermoPest covers the whole UK, said he is dealing with double the number of callouts for bedbugs this year. Chemical sprays using insecticide are a common method to kill bedbugs, but there is growing evidence that the insects are becoming increasingly resistant.
Rhoades, who offers high-heat treatment rather than chemicals, reported a 30% increase in customers coming to them after a failed professional pest control treatment. He told Metro: “Year on year, we are seeing more cases where people are coming to us. The data definitely suggests that there is a lot more resistance to chemicals than there ever has been.” Rhoades added that he had heard stories of bedbugs being sprayed with chemicals and “just running around like nothing’s happened.”
Expert Insights on Resistance
World-renowned bedbug expert Chow-Yang Lee said insecticide resistance was “probably the single most important reason” infestations have “increased dramatically over the year.” He told Metro: “The insecticides used to kill bedbugs increasingly fail to do so, and insecticide resistance is now a leading cause of control failures.” He noted that the pyrethroid class of chemicals was particularly ineffective.
Prof Lee continued: “This pushes up infestation numbers in two ways. First, when a treatment doesn’t fully work, the infestation isn’t cleared. Bedbugs survive, keep breeding, and can spread into other rooms or neighboring homes. Second, and more insidiously, every time a population is hit with a chemical it can withstand, the few weakest bugs die, and the toughest survive to reproduce. Repeat that over many treatments and you’re left with a population that’s almost entirely resistant.”
While bedbug resistance has always been a problem, the challenge is that resistance “has deepened, broadened across chemical types and become much harder to overcome.”
London at the Heart of Resurgence
London is at the heart of the global resurgence of bedbugs due to the capital’s housing density, international tourism, and large rental market. Since the return of worldwide travel after the Covid pandemic, some London boroughs have faced more than double the number of bedbug infestations. One local authority had only 84 infestations in 2021 but as many as 441 in 2023.
Dr Matthew Davies, an advisor to the Greater London Pest Liaison Group, told Metro that this rise has continued into 2026. The expert, who is Head of the Technical Department at Killgerm Chemicals, blamed the problem in part on a drop in insecticides on the market, making it harder to tackle resistance. Dr Davies stressed that resistance is not a “doomsday scenario where there are no available options.” Instead, the key to success is an “integrated” treatment solution using different strategies at once. He explained that alongside chemicals, “this includes steam treatments, heat treatments, and monitoring for problems with lures.”
Impact of Cost-of-Living Crisis
There are also fears that the cost-of-living crisis is pushing more families to avoid professional bedbug treatments. Many are turning to DIY methods, which often worsen the problem. Prof Lee said people are “falling back on cheaper sprays, including shop-bought foggers and aerosols that barely work. Every one of those partial treatments does two unhelpful things: it leaves enough insects alive to keep the infestation going, and it kills only the susceptible individuals, leaving the resistant ones to survive and breed. In other words, over-relying on insecticides that no longer fully work is actively making the resistance problem worse.”
