Pest control products manufacturer, Lodi UK, has said rodent numbers have risen sharply following Covid-19 and, as temperatures fall, rodents will seek shelter on farms.

If not controlled, the company said, rodents could ruin grain stores.

Lodi UK pest control specialist, David Reece, said: “Farmers should take an integrated pest management approach and use a variety of baits to combat resistant rats and prevent infestations that can result in grain losses and contamination.”

Lodi warned that rats can thrive in a grain store and multiply quickly, with one breeding pair escalating to 1,250 in just one year.

Reece said protecting grain stores does not have to involve the use of rodenticides, and farmers should select bait carefully to avoid wasting money baiting resistant rats.

Farmers can take many non-chemical measures such as proofing buildings, identifying areas that rodents may be using for harbourage and making regular checks by walking the farm,” he said.

“Rodenticides should contain actives such as cholecalciferol or brodifacoum because some rats are now resistant to the previously popular actives bromadiolone and difenacoum.”


Lodi and Reece’s first tip for farmers is to look for signs of rats and mice – this includes checking for droppings and gnaw marks.

Reece is encouraging farmers to make a farm plan and regularly walk their farm to look for burrows and record where rodent activity is apparent.

“Just because there are signs of rodents it doesn’t mean baiting in that area will always be totally effective,” he said.

“Understanding areas that rodents are using to access food and water can help make trapping or baiting much more effective.”

The second tip is to keep farm buildings and sheds free from clutter and rubbish.

Lodi said rats do not like open spaces, so farmers can reduce rodent activity by keeping their farm, especially areas around grain stores, clear of rubbish, weeds and objects that rats can use for harbourage.

“Although a simple process, keeping a farm tidy by removing rubbish can make a big difference,” Reese said.

“Preventing access to food and water by securely storing food, repairing dripping taps and making sure there is no food available outside will reduce the likelihood of rats seeking harbourage and breeding on a farm.”

Rodent control

Another tip from the pest control company is to ensure farm buildings have no access points for rodents to reduce the risk of infestation.

“Small measures like using mesh smaller than 10mm to cover gaps in grain stores will help to prevent both mice and rats gaining access,” Reece said.

The fourth tip is to establish bait boxes at least four weeks ahead of baiting at it will reduce a rat’s neophobic behaviour (a fear of new objects) and improve bait take.

“Rats have a fear of new objects (neophobia). Therefore, placing boxes ahead of time and even adding non-toxic bait can help the boxes become trusted,” Reece said.

Reece’s final tip is that rodenticides be used when non-chemical methods have been exhausted.

However, these should rodent controls should be carried out methodically and carefully, he said.

“The fastest acting bait available is Harmonix which contains cholecalciferol and can control a rodent infestation in just 7 days. It is not an anticoagulant so can be used inside and out, and also poses less threat to non-target species such as birds and other wildlife,” he said.

 Using a bait that is highly palatable is a particularly important consideration in grain stores where food is plentiful, Lodi said.

“Harmonix or Lodi Gems Sapphire both have a highly palatable wheat-based formulation that make it more appealing to rodents and represent the best choice for grain stores,” Reece said.