Reducing the negative impacts and improving efficiency of rat pest control

Control of invasive rodents is a major global challenge, particularly for species such as brown rats (Rattus norvegicus) that exploit a wide range of habitats associated with human activity. The most prevalent rat across Europe and North America, brown rats have profoundly negative impacts through crop and food damage, are vectors of diseases with significant human and livestock health risks, inflict expensive damage to the built environment and cause harm to native wildlife. Economic costs run into many billions of pounds worldwide. Reduction of harbourage and available food help minimise rat problems, but current control strategies rely heavily on highly toxic rodenticides with delayed action to ensure a lethal dose. However, these rodenticides are also highly toxic to other animals and have markedly inhumane effects on target and non-target animals. Despite precautions, poisoning of non-target wildlife is widespread, with highly persistent anticoagulant rodenticides causing secondary poisoning in a high proportion of avian and mammalian predators. A major issue is that non-target rodents (field voles, bank voles, wood mice in UK), which are the main prey of many raptors and mammalian predators, easily access rat baits even in tamper-proof bait boxes. While brown rats show substantial wariness towards baits and traps, leading to a long delay before interaction with control measures, non-target rodents access these baits very quickly. There is urgent need to reduce primary and secondary poisoning of non-target animals and to target rat control much more effectively to allow quick control when rats first invade.
We will develop tools to protect non-target rodents from rodenticides whilst simultaneously overcoming the substantial caution of rats towards control measures. To achieve this, we will develop scents that (1) overcome neophobia in brown rats and attract them to enter boxes housing baits or traps, and (2) deter non-target rodents from taking rat baits. Deployment of this approach at scale for commercial application requires the development of synthetic mimics of natural scents that are very effective. Using bioassays conducted in large outdoor enclosures under realistic semi-natural conditions, we will optimise these synthetic mimics for both attracting rats and deterring the three main UK non-target rodent species. The most successful mimics will then be field tested in natural rodent populations, and next stages for development discussed with regulators and the pest control industry. For ethical and environmental reasons, all work will involve non-toxic monitoring baits that do not contain rodenticides.
Successful development of this approach will improve the efficacy and humaneness of rat control while reducing environmental harm. It will help protect authorised use and sustainability of important rodenticide products, substantially reduce loss of baits taken by non-target rodents, and allow more effective monitoring of rat activity.  An effective rat lure will improve efficiency of control, reducing environmental health risks, rat damage and the number of animals that must be killed. It will also work with next generation control products that may be developed, such as chemical contraceptive or sterilant baits, humane rodenticides and traps. Protecting non-target rodents also protects vulnerable predators from reduced food supply and secondary poisoning. Beneficiaries will include general public, public services and private industry concerned about rat damage and health risks; food producers and retailers; new products for pest control manufacturers, distributors and service industry; regulators and public concerned about biodiversity loss and humaneness of rodent control.