Guide

Rats, Farm Feed and the Law: Protecting Stores, Biosecurity and Your Duties

Rats foul far more feed than they eat, carry disease that affects livestock and people, and bring a legal duty most farmers don't realise they have. This guide covers what rats cost you in spoiled feed, the biosecurity and disease risks, your obligations under the Prevention of Damage by Pests Act 1949, and how to protect feed stores the right way.

The short version

Rats are an expensive problem in a feed store for three reasons: they contaminate far more feed than they eat, they spread disease to livestock and people, and as the occupier of the land you have a legal duty to keep rats under control. A single mouse can eat around 2kg of feed and contaminate roughly 40kg in a year through droppings and urine, and rats do proportionally more. Protect feed by storing it in sealed containers, proofing the store, baiting in locked stations and keeping records, and you deal with the cost, the disease risk and the legal duty all at once.

What rats actually cost you in a feed store

The feed a rat eats is the small part of the bill. The bigger cost is contamination, because rats foul feed with droppings, urine and hair as they move through it, spoiling far more than they consume. As a rough sense of scale, a single mouse can get through around 2kg of feed and contaminate something like 40kg in a year, and rats, being larger, do more. Livestock will often reject feed that's been fouled, which means wasted feed and animals missing the nutrition they need, with a knock on hit to growth rates and margins.

There's a damage cost too. Rats gnaw constantly to keep their teeth down, so feed bins, store fabric, wiring and equipment all take a battering, and chewed wiring is a recognised fire risk in farm buildings. Put together, an unmanaged rat population in a feed store is a steady drain rather than a one off.

The disease and biosecurity risk

Rats are a biosecurity problem, not just a feed one. They can carry and spread diseases that matter on a livestock farm, and the contamination route is straightforward: rats foul feed and water with urine and droppings, and animals or people then come into contact with it.

The one to know is leptospirosis, the bacterial infection behind Weil's disease, which spreads through rat urine and can affect both livestock and people. It's a genuine human health risk for anyone working around an infested store, which is why handling dead rats with gloves and washing up afterwards matters. Rats can also move salmonella and other pathogens around a holding, and carry mites and fleas. On any farm with an assurance scheme or food safety standard to meet, visible rodent activity around feed is the kind of thing that fails an audit, so keeping on top of it protects your certification as much as your stock.

Your legal duty: the Prevention of Damage by Pests Act 1949

This is the part many farmers don't realise. Under the Prevention of Damage by Pests Act 1949, occupiers of land have a duty to keep it reasonably free from rats and mice, and to take steps to control them where they're present. Local authorities have powers under the Act to require an occupier to take action where rodent activity is a problem, and to act themselves if it isn't dealt with.

In plain terms, keeping rats under control on agricultural land isn't just good practice, it's a legal expectation, and "I didn't know" isn't much of a defence. The practical response is simple and is the same thing that protects your feed and your stock: monitor for activity, act when you find it, and keep a record of what you did. That record is also what demonstrates you've met your duty if a local authority or an assurance scheme ever asks.

How to protect a feed store, step by step

1. Store feed so rats can't reach it. Keep feed in sealed metal bins or secure containers rather than open bags, which rats chew straight through, and keep stores off the floor on pallets or shelving so spillage is easier to spot and clear. Clean up spilled feed promptly, because loose grain is what draws rats in and keeps them fed.

2. Proof the store. Older grain and feed stores are often the weak point, with gaps under doors, worn louvres and holes where pipes pass through. Fit and maintain door seals, mesh vents and louvres with gaps under 10mm, and fill holes with wire wool and a suitable filler. Keep the immediate surroundings clear and open, since rats dislike crossing exposed ground to reach a building.

3. Bait correctly, in and around the buildings. Where activity is present, use locked tamper resistant bait stations placed on the runs and near burrows around the store, kept in and around buildings rather than out in open areas. Bear in mind the rules: rodenticides such as bromadiolone and difenacoum face restrictions on open area use under changes that came in during 2024, and grain based baits should be kept away from where grain is actually stored to avoid cross contamination. Follow the product label, and check the HSE rodenticide guidance for the detail.

4. Monitor, record and clear up. Walk the store regularly, note where you see activity, and keep a written record of where you've baited, which product you used and when you checked. Remove dead rats promptly and dispose of them to the label, both to reduce secondary poisoning of wildlife and to keep the store clean. The record is your evidence of due diligence for assurance schemes and your legal duty alike.

For a feed store or a working farm with several buildings, the Rat Killer Poison Kit Large gives you eight tamper resistant stations and a range of bait formats to cover the store and surrounding buildings at once. For a smallholding or a single store, the Rat Killer Poison Kit Small is usually enough to get on top of activity. The locked stations keep bait secure around livestock, which is exactly what you need around feed.

A note on resistance

If you're baiting and the population isn't dropping, resistance may be the reason. In parts of the UK, particularly the South, rats have developed resistance to some anticoagulant actives, so a bait that should work can underperform. Good bait take but no fall in numbers is the tell. The answer is to review the active and the placement rather than just adding more of the same, because baiting resistant rats with the wrong active wastes money and feeds the problem.

FAQ

How much feed does a rat waste?

Rats contaminate far more feed than they eat. As a sense of scale, a single mouse can eat around 2kg and foul roughly 40kg in a year through droppings and urine, and rats do more, so the contamination loss is usually the bigger cost.

Are farmers legally required to control rats?

Yes. Under the Prevention of Damage by Pests Act 1949, occupiers of land have a duty to keep it reasonably free of rats and mice, and local authorities can require action where there's a problem.

What disease do rats spread on farms?

The main one is leptospirosis, the cause of Weil's disease, which spreads through rat urine and affects both livestock and people. Rats can also carry salmonella and other pathogens, and bring mites and fleas.

How do I keep rats out of stored feed?

Store feed in sealed metal containers off the floor, clean up spillage, proof the store against entry, and bait in locked stations around the buildings if activity is present. Keep grain based bait away from stored grain to avoid cross contamination.

What we'd do next

Start by tightening up storage and proofing the store, since that removes the food and the access in one go. Walk the store regularly and keep a record of what you find and do, which protects you on both the assurance and the legal side. Where rats are active, bait in locked stations in and around the buildings with the Rat Killer Poison Kit Large for a feed store, or the Rat Killer Poison Kit Small for a smaller setup, and clear away any dead rats as you go.