It is a common myth that bed bugs are microscopic, but this is untrue. While they are extremely tiny and prone to hiding, a full-grown, well-fed bed bug is approximately one-fourth to three-eighths of an inch long, which is fully visible to the naked eye, according to the Environmental Protection Agency, or EPA.

Life Stages

A fully grown bedbug is brown, flat, oval and 5.5 mm long. Unhatched bed bug eggs and their shells are only 1 mm long and white, while nymphs, which are young bed bugs, vary from 1.5 to 3 mm and are a lighter shade of brown. A mature male bedbug is also slightly smaller than a female bedbug.

Locating a Bedbug

Even in egg or nymph form, a bed bug is visible if you know where to look. Like their name suggests, bedbugs are often found in beds, particularly in the plastic corner of a box spring, the piping or seams of a mattress, and behind the headboard. Other tell-tale signs include shed skins, which are left by nymphs as they grow into adults; tiny, dark spots of excrement; or rust- or red-colored blood stains, which are the result of crushed bed bugs.

Bite Marks

More often than not, the first discovery of infestation is not the bed bug, but the bite. A bite mark looks a lot like a rash or mosquito bite, which can be misleading and delay treatment. The actual bite mark may appear as a single bite, but most likely will be in a group of three or four red-colored, rash-like spots. An individual's reaction to the bite will vary, but some will experience swelling or itchiness.

Catching them in the Act

A bed bug's most active period, and therefore your best time to catch them in action, is the hour before dawn, according to the website Bed-Bug.org. To locate a bed bug during this time, the website recommends shining a light on the bed, which will help you see them. If you suspect a bed bug infestation but cannot locate the culprit, bug-sniffing dogs can be hired out for roughly $200 to $300 per inspection.