Plan now, save later with effective and responsible measures

If you haven’t started to prepare for the possibility of rodents moving into your pig buildings this autumn and winter, now’s the time to begin, according to the chairman of the Campaign for Responsible Rodenticide Use (CRRU), Dr Alan Buckle

This is a good time of year for pig units to reinforce their defences against the annual migration of rats to farm buildings. Reassessing a farmstead’s rat control measures now can save a great deal of time and money later. Otherwise, incidents of rodenticide misuse, even if unintended, could expose vulnerable wildlife and increase the risk of legislation that could restrict farmers’ future options.
“When you meet farmers individually and tell them that up to 90% of kestrels and owls on their farms are probably carrying residues of rodenticides as a direct result of their own or a neighbour’s poor practice, they are genuinely shocked,” says Dr Alan Buckle, who heads the CRRU, which has been charged by the Health & Safety Executive (HSE) with developing a stewardship scheme for the use of second-generation anticoagulant rodenticides. “With this in mind, autumn is a good time of year to renew defences against rats.
“Two options to achieve an effective result responsibly are either to bring in a qualified rural pest controller or take DIY action that follows the CRRU code of practice. Either way, the first job is to check farm buildings and surrounding areas, noting evidence of rodent activity and other relevant aspects, such as high-risk locations, attractive harbourage and feeding sites.
“If fresh evidence of rats is found, then write down a control plan of how the infestation is to be tackled. This should identify suitable places for baiting points, all of which must be protected.”
Dr Buckle emphasises that a site map on which all bait points are marked is important to assist with monitoring of treatments and demonstrate good practice. All control programmes should have a start, middle and end, he adds.
“It may take as few as 14 days and usually no more than a few weeks to clear a rat colony, depending on the severity of infestation,” he says. “At the end of the treatment period, the site must be cleared of all remaining rodenticide, aided by the site plan to make sure no bait points are forgotten. Non-poison bait can be introduced as an early warning system of new infestations, as long as bait points continue to be inspected regularly.
“Meanwhile, all rodenticide products must be used strictly according to the label, alongside non-rodenticide measures including prevention of access to food sources and elimination of refuge sites. Clearly, improper use of rodenticides puts children, staff and pets at serious risk.”
In the event of suspected improper use of rodenticides, and depending on location and circumstances, the HSE and local authorities have responsibility to investigate such incidents and, where appropriate, take enforcement action against those responsible.


  • Always have a planned approach.
  • Always record quantity of bait and where it’s placed.
  • Always use enough baiting points.
  • Always collect and dispose of rodent bodies.
  • Never leave bait exposed to non-target animals and birds.
  • Never fail to inspect bait regularly.
  • Never leave bait down at the end of the treatment.

To reduce the chances of a rat-free site being reinfested, Dr Buckle advises some straightforward house-keeping around the farm. For example, rats will migrate to farm buildings in search of food, but they don’t like to cross bare ground because it gives predators a chance to take them.
“Old pallets, disused farm machinery, wood piles and stacks of old straw bales are all rat-friendly hiding places, and they’ll make straight for these when searching for food in the autumn,” he says.
“Maintaining clear apron areas between buildings and adjacent hedgerows, ditches, or stacks of bales can help prevent rats returning. Repairing the fabric of buildings and closing off entry points will also deter rats from migrating back.”
The reason rats come onto farms in the first place is, of course, food, adds Dr Buckle. He says feed spillage is an obvious but all too common risk factor. On pig units specifically, feed dust that leaks from augers or settles out of the air onto horizontal surfaces is a highly nutritious and attractive food source for rats, so the CRRU chairman urges that cleanliness, indoors and out, is an essential component of keeping rats at bay.
Where pig housing and on-floor grain stores occupy the same site, the latter can have roller doors fitted that will stop rats getting in. However, Dr Buckle points out that, to be effective, this relies on a closed-door-policy followed by everyone on the unit.
“This may be an obvious thing to some, but in reality it’s not observed to a surprising extent, even on units where you’d expect it,” he says.
In addition to being ready for the stewardship programme’s introduction, two other imperatives are that up to half of all farm fires are started by rat damage, according to Dr Buckle, and wherever rats are found, even in very low numbers, people are at risk of exposure to the zoonotic disease organisms they carry. These include Cryptosporidium, Campylobacter, Listeria, Toxoplasma, Salmonella and Leptospira.
When it comes to controlling rats on pig units, Dr Buckle finds the key to success originates not outdoors around the farmstead, but inside the heads of those running the unit.
“Every serious infestation begins with just a few rats,” he says. “So there’s no place for acceptance that all units have a few rats and you just have to put up with them.
“However, when you work on-site every day, it’s understandable if weak-spots are overlooked. One option is to engage a professional pest controller for half-a-day in the autumn to go round the unit with a fresh and expert pair of eyes to point them out. Then you have the option of DIY remedies or buying a bit more professional time, depending on what action is needed.”
For professional help, more than 180 wildlife-aware pest controllers have been trained by CRRU and accredited by BASIS, their contact information can be found at, where more information can also be found to help farmers employing DIY control methods.

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