A recent increase in reports of bedbugs, even in the best establishments, suggests that they can no longer be regarded as only a problem of the past. Although their bites can be a serious irritant, especially for the allergic, they are not known to transmit disease.

With its primary habitat bedding and furniture, the most common species (lectularis) is present throughout the world. Bedbugs feed exclusively on blood from birth to death. Their nocturnal habit and small size makes them difficult to discover, and easy to transport. While they cannot thrive in very cold or very hot weather, in a modern house or apartment they have no season.

Appearing at first glance to be nonsegmented like ticks, bedbugs (and their functionally close relatives, lice) are actually parasitic insects. Yellow-white when young, adults are reddish-brown. They often live in large "colonies", clustering together during the day.

After birth from a large egg mass, the young suck blood (about ten minutes to fill up) and then molt. This process is repeated four of five times before adulthood. The female must then have another meal before she lays her eggs. Since meals are necessary for each stage, and since individuals at each stage can survive for long periods without food, life spans vary widely — from little more than a month to as much as a year.