Bed bugs belong to a family of insects that are primarily human, bat and bird parasites. It is believed that the first bed bugs parasitized bats in ancient Mediterranean caves and began parasitizing humans as they inhabited caves along with bats. As cities were established and commerce between them followed, bed bug infestations became more permanent and spread to other areas. Now, the bed bug (often called the common bed bug) has a worldwide distribution and is the dominant bed bug in temperate climates.
Bed begs do not live on their host like lice and adult fleas. They are nest parasites that live near their host, avoiding light and spending the majority of their lifetime hiding in protected areas. For human hosts, this translates into mostly sleeping or resting areas. As infestations grow, bed bugs are found in less predictable locations, such as closets, hallways, bathrooms and kitchens. The tendency to aggregate also decreases as access to food decreases. At any given time, bed bugs actively move throughout structures, especially adult females.
Different bed bug populations can show resistance to different insecticide modes of action, depending on which products are repeatedly applied in certain cities or regions. Combination products are available that contain more than one active ingredient with different modes of action to help fight resistance. Bed bugs usually die from direct insecticide applications but must sit on dry residues, sometimes for several days, in order to receive lethal doses. For quicker results, insecticides should be applied directly to bed bugs and their harborages.