Don't let bed bugs hitch a ride on your dirty clothes
Keeping dirty laundry in the bedroom allows bed bugs to thrive because they are attracted to soiled clothing.
According to a new study, numbers of the nocturnal blood-sucking insects have soared in recent years, largely because of low-cost international travel, which has allowed them to spread between countries.
The parasites are a headache for hotel owners because infestations are difficult to spot until the bugs start biting.
However, the study by the University of Sheffield has shown that the insects are drawn to dirty laundry, which could be their method of "hitchhiking" between countries.
Dr William Hentley, of the university's department of animal and plant sciences, advised against leaving clothes exposed in sleeping areas.
"Bed bugs are a huge problem for hotel and home owners, particularly in some of the world's biggest and busiest cities," he said.
"Once a room is infested with bed bugs, they can be very difficult to get rid of and can result in people having to dispose of clothes and furniture, which can be really costly.
"Our study suggests that keeping dirty laundry in a sealed bag, particularly when staying in a hotel, could reduce the chances of people taking bed bugs home with them, which may reduce the spread of infestations."
In the study, published in Scientific Reports, experiments were carried out in two identical, temperature-controlled rooms, in which four tote bags were placed in the presence of bed bugs.
Two contained soiled clothes and the others clean. In each test, one room received an increase in concentration of CO2 to simulate human breathing.
In the absence of a human host, bed bugs were twice as likely to aggregate on bags containing dirty laundry compared with those with the clean clothes.
The findings suggest that the bugs are drawn to residual body odour in dirty laundry, so worn clothes left in an open suitcase or on the floor may attract them.
"It is the first time human odour has been considered as a potential mechanism facilitating long-distance dispersal in bed bugs," said Dr Hentley.
"Bed bugs struggle to walk up smooth surfaces, so when I go travelling I always look for those smooth metal luggage racks to keep my suitcase on. Failing that, I would keep my clothes in a big Ziploc bag."
The common bed bug (cimex lectularius) went into decline in the 1980s and 1990s but has recently undergone an aggressive resurgence, with cases more than doubling during the past few years.
Before feeding, they are a flattened oval shape, light brown and around 5mm long; but after a blood meal, they swell up to become rounder and darker.
They can survive for six months without feeding and, although they are not dangerous, they can cause discomfort and stress to those who are bitten by them. (© Daily Telegraph, London)