It's the females that bite.
Ellen Wilgar learned this while working to keep track of the mosquito population by baring her arms each night in the headlights of a truck and being eaten alive by them.
As a state pest control technician, Wilgar captures, kills and counts mosquitoes -- by letting them feed on her flesh -- to determine if the neighborhoods she patrols in eastern Baltimore County should be sprayed with insecticide.
Some people might see Wilgar's job using herself as live bait as a nightly exercise in pain -- certainly worth more than the $7.70 an hour it pays.
But not Wilgar.
"It's not so bad. You're outside and you can work by yourself and you don't have some boss or supervisor breathing down your neck every minute," said Wilgar, 26.
Wilgar is one of a dozen seasonal pest control technicians setting traps and being bitten as a step toward controlling mosquito populations in the state's most heavily infested areas.
Mosquitoes are also feeding on state workers in Anne Arundel, Charles and St. Mary's counties and throughout the Eastern Shore.
Michael Cantwell, an entomologist with the state Department of Agriculture and Wilgar's boss, said the work is important, but not too many people are itching to do it.
"We need information that's as accurate as possible if we're going to justify spraying," Cantwell said.
The importance of counting mosquitoes and spraying has increased in recent weeks since Hurricane Floyd turned parched fields into bug breeding grounds. Mosquitoes also have made headlines this fall as authorities battle a mosquito-borne disease that killed three people in New York.
"It's something we've always kept a watch on, but there's an increasing interest in it with all that's been going on," said Cant-well.
State health authorities say that mosquito-borne diseases are extremely rare.
St. Louis encephalitis, the disease erroneously blamed by health authorities in the New York fatalities, hasn't been reported in Maryland since 1975 and is so rare that the state no longer monitors for it.
No cases of malaria, a well-known mosquito-borne ailment, have been reported in Maryland since the 1950s.
As a seasonal pest control technician, Wilgar's duties include hanging mosquito traps to track populations in the Dundalk and Middle River areas.
But it is her blood that makes the counts accurate.
"If you've got live, warm-blooded bait, that's much more attractive to a mosquito than a metal trap," said Cantwell.
Because she is pregnant, Wilgar stays away from the insecticide Permethrin that state crews spray from trucks each morning if her counts show heavy numbers.
She does not worry about encephalitis, or other mosquito-borne ailments, because her physician tells her the work poses no risk.
"As long as I keep my doctor informed of everything, I feel like I should be all right," she said.
Wilgar goes out in her truck four nights a week to sites determined by Cantwell based on complaints he receives about mosquitoes.
The traps she hangs are cone-shaped nylon nets that look like black Japanese lanterns, with small battery-powered lights attached at their tip to attract mosquitoes.
Wilgar stops at about four locations each night to set the traps and to perform "landing rate counts," a five-minute ritual during which she parks her truck and bares her arms.
"It's your body heat that attracts them," Wilgar said one night this week, rotating her arms slowly in the headlights.
When a mosquito landed on Wilgar's thumb, she slapped a test-tube laced with chloroform over it. She capped the test tube with a cork to capture the bug, but like most mosquitoes, it managed to bite her before she captured it.
A dozen bites
Some nights she may be bitten once or twice, and other nights she goes home with a dozen bites.
"I don't really know how many times I've been bitten. It's hard to say. I don't really feel them much anymore," Wilgar said.
Wilgar, who was born and raised in Catonsville and lives in Glen Burnie, was working as a medical lab assistant in the spring of 1998 when she saw a newspaper advertisement for the position.
She works after sunset from late May to mid-October and likes it enough that she will probably return next season.
One benefit, she says, is that she's learned a lot about mosquitoes.
"The females are the only ones that bite. They need the protein in the blood to lay their eggs," said Wilgar.
But she has learned even more about people.
"I get all kinds of questions. People want to know when we're spraying, where we're spraying. Some people don't want us to spray. Others want us to spray more," she said.
Arthur Miskimon, a Dundalk bill collector, includes himself in the latter category.
When Wilgar arrived one night this week to set up the traps in a marshy area near Miskimon's back yard, the father of two practically jumped out of his house to complain about the mosquitoes.
"You should see the bites on my kids' legs," said Miskimon, 30.
Miskimon said that his Dundalk neighborhood is so infested that he sleeps with his windows closed. Otherwise, the mosquitoes get in through the screens and bite the children in their sleep.
"It's the worst I've ever seen it," said Miskimon.
Wilgar handed Miskimon a card with Cantwell's office telephone number to report his concerns.
Such encounters are common, Wilgar said.
"People don't hesitate to come up to you," she said. "They get really excited about mosquitoes."
The telephone number to report mosquito problems is 301-927-8357.