We have a lot of rats around our feed hoppers and cover crops this winter. Can you suggest ways of controlling them?

THE SPARSHOLT TEAM replies: Spring is a good time to get on top of any rat infestations and, ideally, before the vegetation starts to grow again, especially whilst they’re concentrated and not 
dispersed along your hedgerows. As well as eating lots of grain, spreading diseases and causing damage to hoppers and equipment, rats are an underestimated predator of eggs and chicks.

Fortunately, we have a wide armoury of techniques we can use against rats and the best approach is to use as many of them as you can. Although rodenticides can be very effective, their use in the open countryside is restricted and therefore these days should be seen as a last resort.

Whilst you’re still feeding and using your hoppers, you could place a spring trap in a wooden tunnel at each hopper. These will account for quite a few rats over the season, but will need checking every day so can be quite a burden, particularly for a part-time keeper.

Where the rats are concentrated try using a pack of terriers and an old chainsaw to smoke the rats out. As when ferreting, you should work along a hedgerow in one direction and systematically block any burrows that have already been smoked.

Finally, if the above hasn’t worked you could use rodenticides, but you must ensure that your particular product is approved for outdoor use and follow the instructions on the label to the letter. Unfortunately many rat populations have developed immunity to some of the approved second generation anticoagulant rodenticides, so it is wise to check which ones work in your area. The best option is to place the bait directly in their burrows. To ensure the rats eat the rodenticide they should have no access to other feedstuffs, especially maize.