What Do Bed Bugs Look Like?

Bed Bug Identification: Bed bugs are visible, about 5mm long, flat, and oval.

Bed bugs, sometimes described by the European spelling as bedbugs, are the scourge of hotels, hospitals, nursing homes, apartments, single family residences, and just about any area occupied by humans. The scientific name is Cimex lectularius Linnaeus and the Spanish common name is chinche de coma. Contrary to the myth, adult bed bugs are visible.

Adult bed bugs are about 3/16” or just under 5mm in length and are oval and flat. When fed, the bed bug can swell in height so that there is no longer an appearance of it being flat. Bed bugs can range in color depending on many factors including time after most recent blood meal. The colors range from nearly opaque to red to mahogany to deep purple. Earlier stages of life, such as newly hatched nymphs are very small and difficult to see.

Bed bugs have six legs as do all insects. Bed bugs hide during daylight hours and come out at night so it is not common to observe bed bugs during the day as one would for ants or roaches. Bed bugs do not fly as they have no wings and move by crawling or “hitchhiking” on baggage or items carried by humans including clothing.

Bed bugs hatch from eggs and then grow and develop as nymphs. For each stage, or to shed the shell into a new nymphal stage, the bed bug must feed on blood. They prefer human blood.

After being nearly eradicated in the 1960s in the United States, bed bugs have enjoyed resurgence in recent years and there appears to be no end in sight.

Read about other bugs that look like bed bugs.

Frontal close up view of a bed bug:

Anatomy

When they feed, bed bug bodies swell in height
Bed bugs are insects and so they have six legs and three body parts. The body parts include the head, the thorax, and the abdomen. Bed bugs belong to the order hemiptera which includes true bugs.

Many true bugs are flightless, but the distinguishing characteristic of this order is the piercing sucking mouthparts. Many true bugs feed on plant sap; however, some, including the bed bug, feed on humans.

The bed bug body is equipped with vestigial wings, meaning that they have undeveloped wings in the form of wing pads. They do not have full wings and cannot fly. The bed bug sole source of propelling is by crawling. They are good hitchhikers, so they use humans and other methods to move where possible.

The six legs of the bed bug are equipped to move on vertical surfaces, although some surfaces are not hospitable to their movement. The legs are not capable of causing the bed bug to jump.

The bed bug head includes the mouthparts which pierce skin and suck blood. The bed bug has two eyes as well as short antennae. The bed bug looks similar to other similar insects such as the bat bug with the distinguishing characteristics are found on the hairs on the head.

The bed bug body is flat as an adult and late instar nymph (juvenile). Late instar nymphs look similar to adults with flat bodies. When they feed, the bodies swell in height and to a lesser extent, length. A bed bug feeds to repletion in approximately 3 to 10 minutes. Blood meals are required for the bed bug to move to the next stage of development. Both male and female bed bugs feed and may feed several times per life stage.

The male has a pointed tip of the abdomen, and the female has a rounded tip. These distinguish the bed bugs when gender surveys are being done. Females lay eggs from the end of the abdomen and can lay over 400 eggs in her lifetime.