Climate change will increase rat population says majority of rural professionals

An 80 per cent majority of pest controllers, farmers and gamekeepers believe climate change will have an impact on the UK rat population, according to a survey by the Campaign for Responsible Rodenticide Use (CRRU) at the Game Fair. Among that majority, 92 per cent say they expect the impact to be an increase in rat numbers.

Right now, based on evidence they see in their work, 61 per cent of participants say the rat population is rising, while 30 per cent reckon it is static and 9 per cent believe it to be falling.

CRRU chairman Dr Alan Buckle is concerned by the low awareness identified by the survey of two major consequences of rat infestations. Asked about disease organisms carried by rats, while 80 per cent of people named Weil’s disease or its causative agent, Leptospira, only five per cent mentioned Salmonella and no one at all mentioned Campylobacter, Cryptosporidium, Listeria or Toxoplasma.

About the fire risk created by rats, only nine per cent of participants answered correctly that an estimated half of all farm fires were started by rat damage. The majority of participants underestimated the threat, with 68 per cent saying one-in-ten fires and another 14 per cent saying one-in-four.

Advice on the responsible and effective use of rodenticides is available at the CRRU website (www.thinkwildlife.org.uk), the core of which is a seven-point code of good practice: ALWAYS (1) have a planned approach, (2) record quantity of bait & where it is placed, (3) use enough baiting points, and (4) collect and dispose of rodent bodies. NEVER (5) leave bait exposed to non-target animals and birds, (6) fail to inspect bait regularly, (7) leave bait down at the end of the treatment.

In addition to disease and fire risks, Dr Buckle points out that the estimated 10.5 million UK rat population consumes 210 tonnes of food a day, and an infestation of only 10 rats produces 146,000 droppings and 54 litres of urine in a year. He says the estimated annual cost of on-farm damage caused by rats is in the range £15-30 million.


At a number of rural colleges, the 2008/9 academic year sees a training programme about responsible and effective use of rodenticides, developed by CRRU and Sparsholt College, Hampshire, being taught for the first time to students on game, wildlife and countryside management courses.