For British rats, the worst of times has turned out to be the best of times. The vermin more associated with the Dickensian era than modern Britain are thriving, with shuttered shops and half-built housing sites to live in, rotting piles of uncollected garbage for dinner and fewer exterminators sent out to kill them.

"Sometimes I drive into the car park and there are at least 20 of them in the bins," said Paul Hood, 46, a north London resident. "You see them running away in the headlights. During the day, they just sit in the bushes sunbathing."

As the biggest economic bust in 60 years fostered a boom for rodents, municipalities were called an estimated 700,000 times to deal with infestations in the past 12 months, compared with 650,000 the previous year, said Peter Crowden, chairman of National Pest Technicians Association.

The rat population has swollen by 13% this year to more than 50 million, one for every person living in England. Rats and mice are capable of spreading more than 35 diseases, including a fever-inducing nausea and muscle aches passed to humans either via a bite or the rodent's urine.

"The government needs to look at this," Crowden said. "Budgets are being cut. If they don't do something, it's going to be a serious public-health risk."

The British economy is expected to shrink 3.5% this year, chancellor of the exchequer Alistair Darling told parliament in his budget speech last week. The housing market slump has starved local authorities of property development and planning fees that they used to fund services like waste-removal. Weekly collections at 12.5 million British homes fell 7.1% in the last three months of 2008 from a year earlier, according to government data compiler WasteDataFlow. Those providing services on a biweekly basis increased 32%.

"They jump out of the bins," said Jason Goodright, 36, a neighbour of Hood at Larch Close in north London. "People are frightened and just throw rubbish from a distance onto the ground, making the situation worse."

UK councils, which have a total income of £106bn (€118bn), face a deficit of up to £7bn this year because of the decline in building work, according to property consultants EC Harris LLP.

The recession is also leading to more empty shops and unfinished homes across Britain as businesses collapse. More than four out of five councils are currently reporting an increase in empty properties, according to the LGA.

A record 15% of British stores will be vacant by the end of 2009 as 1,600 retailers go out of business, according to the world's biggest credit-checking company, Experian. "Wherever there are empty properties, there's a problem," said Kevin Higgins, a spokesman for the trade group British Pest Control Association. "It's not just rodents, it's cockroaches as well. It'll have a big effect as time goes on."

And it's not just affecting vacated buildings. Gurinder Sahni, director of Master Traders, which exports ethnic food to mainland Europe from London, said he's lost about £500-worth of goods, including almonds, fruit juice and even palm oil, to rats during the past year.

"They come in at night and just eat everything," said Sahni. "There's no favourite. They'll eat anything."

Enquiries from homeowners are rising at Rentokil, the world's biggest rat-catcher, said Savvas Othon, who is in charge of developing the company's new pest-control techniques in the UK. Rentokil's products include pasta-based and chocolate-scented rat baits as well as traps set off when a rodent breaks an infrared beam.

As the downturn bites, consumers and businesses are looking for ways to cut exterminator costs, including trying home-grown solutions, not always successfully.

"We're coming across people putting down improvised traps and over-the-counter products and finding they're not getting success," said Jim England, head of London-based Protex Pest Control. "Inevitably, they end up having to get us in. It costs them more in the end."

Hood in north London relies on his two Jack Russell terriers to get the job done. "They catch one every other day," he said. "They kill more than the pest controller."

The most common complaint to councils involves the brown, or Norwegian, rat. The brown rat can breed throughout the year, with a female producing up to five litters during that period of as many as a dozen babies.

Damage to infrastructure caused by rats, which can harm buildings by burrowing underneath their foundations, costs the UK economy as much as £209m a year, according to the Chartered Institute of Environment Health.

"If we aren't careful, the recession will play into the hands of both rats and mice," Crowden said. (Bloomberg)