Shuttered Homes, Thriving Wildlife

But Prince William has only one inspector working on mosquito abatement, and he is assigned to county swimming pools, said environmental health manager John Meehan. Meehan is looking to have a second inspector, anticipating hundreds of calls in the summer. The county has had only a few cases of West Nile virus in recent years, he said, but it's more of a concern this summer. "The risk is increasing with these vacant and unmaintained homes," Meehan said.

And new residents aren't filling up the empty houses fast enough. Although home sales in the county increased 14 percent from January through April compared with the same period last year, foreclosures in the county have gone up 211 percent in that time. There were 645 foreclosures last month in Prince William, Manassas and Manassas Park, court records show.

That is contributing to a fourfold increase this year in the number of complaints about tall grass in the county, Casciato said. She estimates that Prince William will need to set aside $1.2 million for mowing in the summer, assuming the grass will need to be cut three times, and that half the unoccupied houses in the county will be maintained by banks, real estate agents or whoever else is in charge of the job. Whenever the grass grows higher than 12 inches, Casciato's office must contract a mowing company at a cost of up to $150 per half-acre lot.

"We're hopeful that the real estate community and banking community will do what they can with the property entrusted in their care," Casciato said. "For the ones where that is not the case, we're calling on the community to help us locate those."

Fairfax has been slammed with tall-grass complaints, too. Spokesman Brian Worthy said officials have received 516 such calls in the past three weeks, compared with 900 in all of 2007. "We've got a lot of uncut grass," he said, adding that many property owners are complying with violation notices.

Counties don't provide landscaping services for free, and they try to recover mowing and maintenance costs through special levies or liens on properties serviced. In some cases, they even attempt to garnish property owners' wages. The debt must be squared before a new owner can take legal possession of the property.

The process is rarely swift. "These properties are basically in limbo," said Ron Pereira, general manager of the Lake Ridge Homeowners Association in Prince William. "The banks are so flooded with foreclosures that it takes them months to do something."

Frustration and impatience have turned some residents into lawn-care vigilantes, who attack the blighted yards with their own mowers and implements. Technically, it's trespassing, but health and safety matters come first.

"You got to protect the little ones," said Calvin McCray, a helicopter repairman who refurbishes lawn mowers in his spare time. He recently sheared the grass at a foreclosed house in his Woodbridge neighborhood that kids pass on the way to school, citing concerns that include safety against child and woodland predators. "We've got a lot of foxes running around," he said.

Few of the snakes that residents see are likely to be venomous, said Critter Control's McCombe, who gets about five calls a year for dangerous copperheads. Most of the snakes, he said, are black rat snakes, which are terrific vermin hunters. "They track rodents by the odor of their urine and droppings," he said.

In many suburban neighborhoods, a well-kept yard is a kind of social indicator, evidence of a neighborly covenant and a measure of good morals. These days, Manassas resident Jennifer Hansbrough sees the overgrown lawns in her neighborhood as a depressing economic barometer. It's bad enough that she is seeing more ticks and mosquitoes this year, but the long grass also signifies the $100,000 drop she has seen in her home's value.

"It reminds me the economy is crappy," she said.