International travel is one reason for the re-emergence of bed bugs
The US government is hosting its first-ever bed bug conference amid a comeback by the blood-sucking insects.
Thought to have been virtually eliminated decades ago, bed bugs have re-emerged in dormitories, hospitals, shelters and hotels in several cities.
Bed bugs live in the seams of mattresses, sofas and sheets, emerging to feed on their victims at night.
They are not known to carry diseases, but many people develop an itchy swelling when bitten.
The US Environmental Protection Agency called the two-day summit in the face of rising complaints from landlords, hotel chains and housing authorities, the Associated Press news agency reports.
Bed bugs were last seen in large numbers in the US before World War II.
They have usually associated with impoverished dwellings and inexpensive hotels.
Now, experts say international travel, immigration and changes in pest control practices have contributed to a resurgence of the bug in developed countries.
Dini Miller, an entomologist and bed bug expert at Virginia Polytechnic Institute and State University, told AP there had been a "worldwide resurgence" in bed bugs.
"I can't tell you how many people have spent the night in their bath tubs because they are so freaked out by bed bugs," she said.
Researchers say one of the main problems is that there are few chemicals approved for use on mattresses that are effective at killing bed bugs.
The EPA has withdrawn many of the chemicals over the last 50 years because of health and environmental concerns.