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Insects and other arthropods

Prevention and detection of bed bugs

The bed bug is an ectoparasite of humans, meaning that it lives on or near human beings.
Photo: Public Health Image Library (Piotr Naskrecki)
Cimex lectularius, cosmopolitan.

Bed bugs usually live in small groups and spend their days hidden in the cracks and crevices of a house. They can also be found on furniture, mattresses, door frames, windowsills, pictures and light switches.


The best weapons for keeping bed bugs away are information and prevention. Here are some possible solutions:

  • Examine anything that comes into your home meticulously. When in doubt, don’t bring it inside.
  • Avoid buying used mattresses.
  • Carefully inspect second-hand furniture, clothing and books.
  • Caulk any cracks and crevices in the walls and floor as well as the holes where plumbing and wires go through the wall.
  • Remember that public areas (hotels, homes, hospitals, movie theatres, airports, train stations, buses and taxis) can be temporary refuges for bed bugs. They can hide in clothing, luggage and personal effects and be transported from one place to another without being noticed.
  • Check your luggage when you return from a trip. If necessary, clean your luggage using a vacuum cleaner (dispose of the vacuum cleaner bag just afterwards, placing it in a sealed plastic bag).


Bed bugs are nocturnal and it is rare to see them in open areas during the daytime. Here’s how you can tell if there are bed bugs in your home:

  • Look for immature stages of the insect as well as adults. Piles of yellowish eggs or larval skins (dry, translucent envelopes left behind after moulting) are indicators of their presence.
  • Bed bugs are lucifugous (afraid of light), so a high-intensity flashlight can scare them out of their hiding places. When they come out, vacuum them up.
  • Adult bed bugs are often associated with an unusual odour that reminds some people of fresh raspberries. Other people perceive it as a sickly sweet smell.
  • In places where bed bugs are found, there are usually small, reddish stains that may be dry or viscous. This is blood that has been regurgitated by adult bed bugs.

What you need to know

  • Considering bedbugs’ gregarious behaviour, their odorous glands and the fact that they seek out communal shelter, it is likely that they have a complex system of communication. The chemistry and mechanisms of this system are still little known, but we know that bedbugs produce an aggregation pheromone (an odorous substance which causes them to gather together) and an alarm pheromone that warns other bedbugs of immediate danger.
  • Dogs are trained to track bed bugs and they do a great job of it – they can inspect a hotel room in one minute with a 90 per cent success rate and even detect small infestations!

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