HL Deb 18 December 2000 vol 620 c33WA
Lord Hardy of Wath

asked Her Majesty's Government:

What is their estimate of the brown rat population in England; whether the population is increasing; and whether there is a noticeable increase in the immunity of the species to poisons containing warfarin. [HL56]

Baroness Hayman

A report published by the Joint Nature Conservation Committee in 1995 estimated the brown rat population in England at 5¼ million. No figures on trends over recent years are available. Information on the level of rodent infestation was collected as part of the Department of the Environment, Transport and the Regions' 1996 English House Condition Survey and published in January 2000. The results show that, in general, the level of rodent infestations is low, and is lower compared to a previous survey in 1993. Overall, the 1996 survey found that 1.7 per cent of properties had rats present outside and 0.4 per cent had rats inside. The detailed results are available in the report "Rodent infestations in domestic properties in England", a copy of which is in the Library of the House.

Under the provisions of the Prevention of Damage by Pests Act 1949, local authorities are responsible, as far as is practicable, for keeping their district free of rodents. They also have powers to require occupiers of land to keep their land free from rodents.

Surveillance by the Ministry of Agriculture, Fisheries and Food has shown that in some parts of the country rats are resistant to warfarin; however, stronger "second generation" anticoagulant rodenticides are available for the control of warfarin-resistant rats. In addition to lethal methods of control, heavy emphasis is placed throughout the pest control industry on the need to maintain hygiene and to proof premises against the entry of rodents.