Rat infestations on rise as new control rules take effect

Resistance to rodenticides, the increasing complexity of effective control programmes and recent warmer winters have led to a rise in rat and mice infestations across UK farms.

This is according to a rural rodent survey by BASF Pest Control Solutions, which highlights that rodent activity is affecting all farms, often involving multiple species.

The survey highlights that resistance to rodenticides is also an increasing problem, undermining confidence in control programmes and making protecting farms increasingly complex.

See also: Farmers reminded to prepare for rat poison rule changes

Awareness of the 2026 regulatory changes – which required proof of training and certification in order to purchase and administer professional rodenticides – remains low, despite high levels of concern around compliance.

Many farmers have yet to adapt their approach to reflect the changes introduced in January this year, the survey reveals. 

Laurence Barnard, BASF pest control solutions manager, said: “With growing rodenticide resistance and the recent Campaign for Responsible Rodenticide Use [CRRU] changes, taking a proactive, planned approach has never been more important.”

Infestations

Almost all farmers surveyed reported problems with rats and mice, with more than 60% facing infestations of both species simultaneously.

Mixed farms that include both crops and livestock seem especially affected, possibly due to the variety of habitats and food sources that rodents can access on multi-enterprise farms.

“That means control can’t be a one-size-fits-all approach. Farmers need strategies that are continuous and integrated – combining monitoring, proofing, trapping, and careful rodenticide use where necessary,” said Mr Barnard.

Resistance

The infestation rate is set against a backdrop of rodenticide resistance, about which more than 60% of survey respondents were concerned. About 40% reported suspected resistance on their farms.

More than half of farmers also said rodent control had become harder over the past year. 

Key contributing factors, BASF said, included:

• Suspected anticoagulant resistance is reducing confidence in previously reliable products and making effective control harder to achieve.
• Wetter and milder weather supports higher rodent survival and pushes activity closer to farm buildings and sheltered areas.
• Changes to rodenticide use and purchase rules are adding complexity to in-house control and placing greater emphasis on training and compliance.

Regulatory awareness

Although many farmers seek professional support for rodent control, BASF said many still managed infestations themselves.

However, nearly 70% of farmers surveyed were concerned or uncertain about meeting the 2026 rule changes.

Their main worries include reduced access to effective products, more complex paperwork, and the ability to maintain control over infestations.

Despite these concerns, almost half of farmers have yet to adjust their rodent management strategies, taking a “wait-and-see” approach.

This, BASF warned, could increase the risk of growing rodent populations or non-compliant pest control practices.

“For those struggling to comply with the changes, my advice is to undertake a training course like the ones stated on CRRU’s Think Wildlife page, or work with a professional pest controller to implement a thorough integrated pest management approach,” said Mr Barnard.

This not only ensured compliance and best practice, he said, but also “eases the pressure on farmers, allowing them to focus on their core work rather than dealing with rodents and the problems they cause”.