5 tips to protect grain stores from rodents

Farmers are being encouraged to take an integrated approach to grain store pest management – using a mix of methods to combat rodents.

Unless controlled, stored grain could be ruined by rodents seeking harbourage on farms. Rats can thrive in a grain store and multiply quickly, with one breeding pair escalating to 1,250 in just one year.

“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,” says David Reece, of pest control specialist LODI.

Mr Reece suggests that 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.

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

Mr Reece has five tips to protect grain stores from rodents:

1. Look for signs of rats and mice such as droppings and gnaw marks. Make a farm plan and regularly walk the 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. Understanding areas that rodents are using to access food and water can help make trapping or baiting much more effective.
2. Rats do not like open spaces, so farmers can reduce 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. 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.
3. Proofing a building by ensuring there are no access points for rodents will help 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.
4. Establishing bait boxes at least four weeks ahead of baiting will reduce rat’s neophobic behaviour and improve bait take. Rats have a fear of new objects – a condition known as neophobia. Therefore, placing boxes ahead of time and even adding non-toxic bait can help the boxes become trusted.
5. When non-chemical methods have been exhausted, the use of rodenticides to control rats and mice should be carried out methodically and carefully. Fast-acting bait Harmonix contains cholecalciferol and can control a rodent infestation in just seven days. It is not an anticoagulant so can be used inside and out – and poses less threat to non-target species such as birds. Using a bait that is highly palatable and appealing to rodents is a particularly important consideration in grain stores where food is plentiful.