The true origin of, "Sleep tight, don't let the bedbugs bite," is unknown, but it's a nighttime sentiment proving increasingly appropriate these days.

In the past few years, the bedbug population has soared -- by 500 percent, according to a bill in Congress aimed at putting some federal resources behind the problem (otherwise known as the Don't Let the Bed Bugs Bite Act of 2009, or simply HR 2248). At the same time, calls to exterminators about bedbugs are up 57 percent nationwide, according to a survey by the National Pest Management Association and the University of Kentucky.

For now, ground zero for the bedbug infestation appears to be New York City, where 6 percent of households said they had battled these critters in the last year, according to a 2009 city community health survey. The survey's results, released to The Associated Press in late July, revealed nearly 11,000 complaints about bedbugs in fiscal 2009 -- up from only 537 complaints in 2004.

But there's more: This epidemic in New York City may have to do with the unusually high temperatures this summer. Mark Brown, a bedbug specialist from Bed Bugs NYC, told that "bedbugs peak in the heat," and July and August are typically the biggest months for the tiny critters. "Bedbugs tend to come out in the heat because they get dehydrated and more thirsty," said Brown. "In the winter, they typically slow down and hibernate."

The truth is that bedbugs have gorged themselves on sleeping humans for thousands of years, according to the Mayo Clinic. But after World War II, the problem came under control with the use of the pesticide DDT, which has been banned in recent decades because of its toxicity.

Though bedbugs feast on blood, they aren't fatal and don't spread disease -- but they are still a problem. Bedbug victims can lose lots of sleep, and become very anxious or even panic-stricken, says Susan Jones, an associate professor of entomology at Ohio State University. And the 50 to 70 percent of people allergic to the bites will develop itchy, red bumps.

Also, there is a stigma when it comes to being infested with bedbugs, as Jones described in a story from Daily Finance: "Ticks and mosquitoes bite us when we're outside, in their world, but bedbugs invade the safety and sanctity of our homes. We see our homes as a sanctum. Bedbugs hide in our spaces and come out at night to feed on us."

Given the severity of this issue, New York City is taking action. The city's Bed Bug Advisory Board released a report in late July that recommends increasing public education on how to detect and eliminate the pests, for which the city will re-appropriate $500,000 in the Department of Health and Mental Hygiene's budget to fund the education and outreach effort, which includes a new bedbug team within the department.

Other report recommendations include launching and maintaining an online bedbug portal devoted to bedbug facts and resources, similar to the city's rat portal; assembling a bedbug team to coordinate the city's bedbug efforts through the Department of Health; and requiring landlords to provide written bedbug information to tenants upon lease signing and renewal, to name a few.

While local officials continue looking for ways to stem the epidemic, many Americans are revisiting that bedtime rhyme and sleeping a little tighter these days.