Out for blood: Growing numbers of bed bugs, mosquitoes and ticks are spreading misery and frustrating lawmakers.

• Author: Winter, Mary
• Position: HEALTH AND ENVIRONMENT

Like vampires, bed bugs feed on human blood, do their best work at night and are very hard to kill. Also like vampires--at least those on TV and movie screens--bed bugs have made a mysterious comeback in the past decade.

The United States "is now experiencing an alarming resurgence in the population of bed bugs," the Centers for Disease Control and Prevention and the Environmental Protection Agency announced in May. Unfortunately, they're not the only bugs that have Americans scratching their heads and asking why now? Black-legged ticks are blamed for a surge of Lyme disease, and mosquitoes carrying the West Nile virus plague certain regions, even though their numbers nationally remain stable.

Experts can't say with certainty what's causing the increase, but blood-sucking vermin definitely are on state lawmakers' minds. In the last four years, NCSL data show states have seen more than 100 bills on bed bugs and 92 mosquito-related bills. Nine states have enacted roughly 18 laws pertaining to Lyme disease, according to the Lyme Disease Association.

Night Feeders

Powerful--yet dangerous--pesticides such as DDT all but put an end to bed bugs in the 1950s, but since the late 1990s, they've been multiplying and are found in every state, sending complaints pouring into public health agencies, according to the CDC and EPA. About as big around as an apple seed, but as thin as a credit card, beg bugs hide in mattress seams, bed frames, headboards, cracks in furniture and behind wallpaper. They come out at night to feed on human and animal blood, typically leaving red, itchy welts where they bite. Bed bugs aren't known to carry diseases, but they can cause infections and are costly to governments and businesses. Worst of all is the human suffering they cause, says Representative Dale Mallory (D) of Ohio.

"The stories are endless. People burn their houses down to get rid of bed bugs. People sleep in bathtubs. Kids are sent home from school with their coats in plastic bags," he says. Mallory lives in Cincinnati, the most bed bug-infested city in the country, according to Terminix pest control company, which ranks cities according to the number of service calls it receives from each.

Soon after Mallory was elected in 2007, a tour of senior housing shocked him. "It was nightmarish," Mallory says. "There were bed bugs falling from the ceiling. It traumatized me. And the more I looked, the more I saw ... It's one of the smartest bugs. It hides and waits for you, then smells your breath, like someone just lit up the barbecue grill."

Bed bugs, which have no natural predators...