I have a garden bordered by a brook with fields beyond. I have seen rats under my shed. This happens most winters now. What can I do?

KT, Staffordshire

During winter, when food becomes scarce and natural cover no longer keeps out the cold, reports of rats in gardens and outbuildings rise. A recent local authority survey found that 25% of rat infestations in domestic premises were caused by food put out for birds and 14% by compost heaps; 10% were linked to domestic animals.

“Environmental management” can work as well as rodenticides. In trials on a farm, rats tagged with radio transmitters broke cover more often when the farm was kept tidy and vegetation cut low. They were more vulnerable to predators and their population fell faster than in the unkempt control area, where rodenticides were used.

If reducing food and shelter does not solve the problem, call in help. Many local authorities offer a free or subsidised service. The British Pest Control Association offers a useful locator at www.bpca.org.uk/DirSearch.asp.

Hardware shops and garden centres offer traps and baits. With both, particularly rodenticides, read the label carefully and comply fully with the instructions. Both present a real risk to wildlife, domestic animals and children if misused.

If you see rats indoors when there is no obvious way in, you may have a drainage problem.

Richard Strand runs Pest Information Consultancy; rstrand@pestinfo.co.uk

Explore Gardens

• Hampton Court Palace Flower Show

• Chelsea Flower Show

Times recommends

• Second homes: credit crunch casualty or money-spinner?
• How I built my own sliding house
• Top 10 incentives for house buyers