On Rats, Refuse, and Recycling

They say that no one is more than a few feet away from a rat, in town or country. In the UK, the distance must be shrinking year by year. The latest National Rodent Survey reveals that, between the reporting years 1998/1999 and 2004/2005, the increase in numbers was three times higher for rats (39%) than for mice (12.5%).¹ These are not pets (white rats) but the brown rat, or Rattus norvegicus. The survey also counts “summer rats,” up by 69%, not because this is a different species but because of a concern that the seasonal pattern of R. norvegicus sightings has changed. Improved standards of human living do not appear to be affecting rat populations in the UK for the better, and a similar picture has been described for Baltimore, MD, where a rat population of 48,420 was estimated in 2004, this being little changed from half a century earlier.²

The UK’s National Pest Technicians Association (NPTA) highlights six factors contributing to the increase.¹ These are not unique to cities, but somehow, rats in the countryside are acceptable, while in towns they are not. The factors are a mix of the individual and the institutional, and there is the occasional clash between ecofriendly activities and pest control. For example, putting out food for wild birds, if done to excess, results in spills that attract rodents. Composting, which the NPTA refers to mischievously as “recycling mania”, can also encourage rats, if done inappropriately. Urban local authority policies have been causing concern too. The Local Government Association is thinking about charges for refuse collection above a certain weight, and as public refuse disposal becomes more complex with European diktats on recycling, it is not unheard of for rubbish bins to be emptied once a fortnight instead of weekly. This policy may encourage recycling and/or rats, and in the city of Oxford, for example, some residents are not at all happy with the change.³

Waste disposal is now a big issue in the UK, where the average annual weight of nonrecyclable refuse is more than 500 kg per household, far more than in any other country in the European Union.⁴ Most of this goes to landfill, and sites are running out. Just as carelessly disposed of food waste in cities attracts rats, urban foxes, and birds, so do landfill sites draw gulls far inland from their usual haunts. When refuse collectors go on strike, cities soon become unbearable, and the residues of half-eaten fast-food meals are a regular feature of city streets today. Happily, there have not yet been epidemics of leptospirosis, hantavirus disease, plague, rabies, salmonella, shigella, campylobacter, toxoplasma, or toxacara infections that can be blamed on unwelcome quadripedal or avian urban visitors. However, the ingredients for threats to public health are in place—for example, in Europe a watchful eye is being kept on the urban fox and human alveolar echinococcosis.^5,6 What does it take to tilt the urban waste problem from the merely unpleasant to the downright dangerous?