Bed bugs have received extensive publicity recently. Reports of the reemergence of this insect have confounded researchers and homeowners alike. In addition, many people who find small bugs anywhere are now calling them bed bugs. So it is important to ask “what do bed bugs look like?” Identification is key to understanding and managing any pest.
Bed bugs have varying appearances depending on the life stage. Most people only seek information about the appearance of adults; however, it is important to understand the appearance of all life stages of bed bugs.
As adults, the most commonly seen stage of life, bed bugs are red to tan to mahogany in color. In fact, they are sometimes called “mahogany flats.” The adults will be more of a crimson color if they have recently fed on blood. They are about three-sixteenths of an inch in diameter when fully grown and if they have not had a blood meal recently, they will be flat. The shape of the bed bug has been described as lentil shaped meaning that looking down on a bed bug, they are rounded.
Insects have three segments: head, thorax, and abdomen. The area of the thorax just behind the head, called the pronotum, has hairs protruding from the sides. These hairs are shorter than the width of the eye. This is important because there is a similar insect called the bat bug which has longer hairs and doesn’t prefer to feed on humans. The hairs are the most distinguishable difference between the two insects.
“Instars” or juvenile bed bugs resemble adults, especially as they reach adulthood. The very youngest of the instar stages are more tube shaped and will swell up in a bulbous fashion after feeding. These younger instars are clearer in color so their engorged color will be closer to blood red. The early instars are very difficult to see, commonly compared to mites due to their size.
Finally, eggs are only about one thirty second of an inch long and are tubular in shape. Each egg contains a “flap” which will act as a door for the hatching process. Most eggs are glued by the mother onto inconspicuous areas such as folds of upholstery or other out of the way places.