Strangers in the night

Despite efforts to eradicate bed bugs, the tiny, sneaky critters continue their invasion of homes, hotels and business across the U.S.

Bed bugs are small wingless insects that feed solely upon the blood of warm-blooded humans and animals. They are about 6-10 mm in length.

A person being repeatedly bitten by bed bugs can be very uncomfortable, develop lots of reddish, itchy welts and often have difficulty sleeping. "The more bugs present, the more bites they inflict, and the worse the problems usually become," says entomologist and bed bug expert Dr. Harold Harlan. "Also, some people can be significantly affected by the social stigma of having a bed bug infestation."

"The most obvious sign of bed bugs are small blackish spots -- or fecal spots -- that look either like pepper of dried blood," says Dr. Dini Miller, a Virginia urban pest management specialist and professor. "It's a sign that bed bugs have digested a blood meal and excreted it right out."

Bed bugs pierce the skin of the host, and inject a fluid which helps them obtain food. This fluid causes the skin to become swollen and itchy.

This photograph of the underside of a mattress box spring (courtesy of the Scherzinger Pest Control of Cincinnati, Ohio) shows a severe infestation. "The white flaky paper-y things are shed bed bug skin," says technical director and entomologist Bery Pannkuk.

These bed bugs (and fecal smears) were found on a cloth mattress protector. Mattress protectors may not completely protect a bed. An adult bed bug is resilient, often able to survive for months without a meal, so infestations sometimes require multiple exterminations.

The tiny vermin avoid light and attack in the middle of the night. They hide behind headboards or in mattress seams during the day. When checking for bed bugs, experts also suggest looking closely at mattress tags and box springs.

The name "bed bug" is somewhat of a misnomer because they do not only live in beds. They can also be found along the edge of carpets, on wooden surfaces, on upholstered furniture, and in this case, within an electrical outlet.

A U.S. Congressional report in 2009 found that bed bug populations increased 500 percent across America in the past few years.