Columbia resident Alice Lewis didn't believe her children when they told her they had seen rats in the yard of her rental townhouse in one of the model community's prototype well-kept, covenant-controlled neighborhoods.
"I said, 'No, we wouldn't have a problem like that here.' And they'd say, 'Yeah, mommy,' " said Ms. Lewis, a Kilimanjaro Road resident in Oakland Mills village.
"I said, 'No, it must be squirrels.' Then one day I looked out the window and saw them in broad daylight, running to and fro."
Ms. Lewis isn't the only Columbia resident surprised to discover rat burrows so close to home. Complaints about rats in the planned city reached an all-time high this year, but environmental health officials say rodent problems were curtailed early this summer.
"They're everywhere, especially any built-up area where there are food sources," said Jim Rawle, Howard County housing code administrator. "Columbia is certainly not an exception."
Frank Skinner, county environmental health director, classifies the situation as a nuisance rather than a health threat.
"It's a concern, obviously," Mr. Skinner said. "We believe the problem we saw earlier this summer is pretty much under control. But with any population you can see a resurgence if certain steps aren't taken."
The bureau has received 54 complaints about rats this year countywide, including 27 from Columbia.
Most complaints from the unincorporated city of 80,000 came since April, Mr. Skinner said.
Ms. Lewis encountered the infestation problem shortly after moving to the townhouse in February with her four children, and says the condition existed before she moved in.
"These weren't small field mice. These were big ones, rodents, the kind you usually see in poor neighborhoods with a bunch of trash around," she said. "I wasn't expecting it to be in a neighborhood where you're paying a good deal of rent and people keep their places clean."
Complaints have been most prevalent from sections of Oakland Mills, Long Reach and Hickory Ridge villages, said health officials.
"They're not crawling out of sewers or anything," said Health Department sanitarian Justina Taylor, who makes many of the field visits. "It's a continual nuisance humans live with. It's been around for eons, and it's going to continue to be around for the rest of the world."
Rats carry several transmittable diseases, but the Health
Department isn't aware of any transmissions to humans this year, Ms. Taylor said.
Mr. Skinner said the rat infestation tends to "wax and wane" and can be contained through increased awareness and cooperation residents and property managers.
One step is to eliminate the rats' food source, which could be leftover dog or cat food, bird feed on the ground, dog manure and garbage that's not contained in metal cans with tight lids.
Ms. Taylor said she had to examine 21 houses on one Hickory Ridge village street in July and August for rat infestation because one resident was lax about leaving dog food and waste on the ground.
Ms. Lewis found that other residents in her neighborhood had similar infestation problems. Ms. Taylor said the Health Department worked for four months to abate "a real headache" in the Kilimanjaro Road area earlier this year.
"It isn't just a minor thing. It's the health and welfare of people who live here," said Ms. Lewis. "If it's not given attention, it won't go away."
The Health Department has worked with homeowners' associations and property managers to bait rat shelters with poison and close burrows, and to educate residents. However, responsibility for abating the problem lies with property owners or renters, not the Health Department.
The department advises sealing holes in structures, stacking lumber or building materials 18 inches above ground and removing shelter, such as high grass and weeds.
Rats indigenous to this area are 7 to 10 inches long with 6- to 8-inch tails, weigh between seven and 18 ounces and have coarse gray, brown or almost black fur.
They live close to people, often near streams or ponds, and burrow where food, water and shelter are available.