Bed bugs (Cimex lectularius Linnaeus) are blood-feeding parasites approximately the size and shape of an apple seed, that feed exclusively on the blood of mammals, with a strong preference for humans and birds,^{[i], [ii]} and to a lesser degree bats, chickens, vermin, and even household pets.^{[iii], [iv]}

The bed bug life cycle includes the egg, nymph, and adult stages, with a total average lifespan of 6-12 months. Because they generally feed at night when their host is inactive, bed bugs are generally found in highest concentrations in dark, dry places near sleeping areas (beds, bed frames, under baseboards, etc), but have been observed to travel up to 20 feet for a meal,^[v] sensing and seeking their hosts through the perception of body temperature and the detection of exhaled carbon dioxide.^[vi]

Bed bugs can be thought of as hitchhikers, being transported between locations on clothing, inside luggage, or on bedding, books, furniture, or any other item brought into your home. They can be picked up in a hotel, dormitory, or any place of residence, or any other location where you may sit for a period of time, such as the office, a movie theater, or a taxicab. Because humans are their preferred hosts, human contact is the most common cause of bed bug proliferation.

Due to their small size and reclusive nature during daylight hours, bed bug infestations can be extremely difficult to control once established. After a blood meal, females lay eggs under the seams or buttons of mattresses, or in cracks, crevices, or any other protected area near the food source. One female bed bug may lay hundreds of eggs over its 6-12 month lifespan, making possible the establishment of a significant infestation from only one healthy female.

Identifying Bed Bugs

Bed bugs are oval, flat (before feeding), wingless insects ranging in length from 1 to 7 millimeters.

Appearance

Bed bugs generally remain well-hidden during daylight hours. However, they may be readily found if one knows where to look.

For pictures of bed bugs at various stages of development and a detailed description of their appearance throughout their life cycle, see below.

The Bed Bug Life Cycle

Eggs are laid by females in tight cracks or crevices or on rough surfaces and covered with a transparent adhesive for stability. Eggs are approximately 1 mm in length, about the size of two grains of salt.

Within two weeks, nymphs emerge from the eggs. At first nymphs are light in color, but they begin to take on their distinctive reddish brown color upon their first feed. Nymphs have the same characteristics as adult bed bugs, but are smaller in size. Nymphs will generally feed once every 7-10 days, and shed their skin after each blood meal. After a series of five molts over the period of 8-10 weeks, the nymphs reach adulthood, and continue to feed on a roughly weekly basis.

Adult bed bugs generally live 4-6 months, but may live longer under some conditions. Bed bugs have two pairs of legs, a short broad head with distinct antennae, and a pair of dark eyes. Females are slightly smaller than males.

The most common locations are:

• Mattresses (especially under the seams)
• Mattress covers (especially the underside)
• Comforters
• Inside box springs, bed frames (wood in particular), and any other part of your bed.
• In general bedroom clutter.
• In furniture (especially cushioned furniture)
• In (or even underneath) carpeting

Other preferred hiding places include:

• Underneath baseboards and around door and window casings
• Behind electrical plates
• Behind picture frames
• Behind wallpaper or wood paneling
• Inside cabinets, suitcases, books, and articles of clothing
• Inside telephones, radios, and clocks (especially those on your night table)

Bite Marks

Bed bug bites are often found in unique patterns – sometimes in straight lines – and often in groupings of three of four. Some have referred to these patterns as “breakfast, lunch, and dinner” patterns. Reactions to bed bug bites include the following symptoms:

• Raised welts, often red
• Itching
• Bite rash in a localized area, often (but not always) on the upper torso where their perception of your exhaled carbon dioxide is stronger
• Bite patterns, as described above

Pictures of bed bug bite marks are available at BedBugs.org. Bite marks are common, but bite marks alone are not enough to confirm a bed bug infestation, since skin irritations may arise from a variety of sources. Additionally, a recent study found that:

“approximately 50-70% of study population would not have any symptoms after first exposure to bed bugs. Subsequent multiple exposures, however, may increase sensitization to bed bug bites in humans.”^[viii]

Skins from Molts

The discovery of eggs, although difficult, indicates the presence or near-presence of an established infestation. Additionally, throughout their lifecycle as described above, bedbugs go through a series of five molts before reaching maturity. Each time a bed bug molts, they leave behind a skin.

Depending on their stage of life, bed bug skins will be of various sizes:

• Egg 1 mm
• 1st stage instar nymph 1.5 mm
• 2nd stage instar nymph 2 mm
• 3rd stage instar nymph 2.5 mm
• 4th stage instar nymph 3 mm
• 5th stage instar nymph 4.5 mm

Bed bugs will shed their skin only after a blood meal, which ideally (for them) is once per week.

Stains on Mattresses

Bed bugs are sometimes crushed while feeding, leaving rusty or reddish-brown stains on sheets and mattresses.

Defecation & Smell

After feeding, bed bugs generally defecate within two hours. Their excrement is composed of discarded blood compounds and will leave black/brown stains about a millimeter in size on bedding, mattresses, and linens.

Bed bugs generally return to their nesting places after a blood meal, so excrement may be found anywhere between their feeding location and hiding place, and in (or very close to) their harborage in particular, where a buildup of feces will generally release a foul odor.

If you find live bed bugs or evidence of bed bugs, stop your search immediately.

If you continue the search, or if you attempt to declutter and reorganize, you may cause the bed bugs to scatter and become more widely disbursed, worsening the problem.

Continuing the search may disturb the nest causing the beg bugs to disburse and hide, further spreading the infestation.

If you find bed bug skins or other evidence, call (705) 749-1045 for a free consultation.

In a 2010 report, the Ontario Agency for Health Protection and Promotion wrote the following:

The possible role of bed bugs in transmission of human diseases has been examined in many studies... It was found that of hepatitis B virus (HBV) DNA may persist for several weeks in the bodies of bed bugs, and it may be present in their feces. However, an attempt to transmit HBV to primates by infected bed bugs failed. Similarly, there were no data to support the potential of transmitting any other infectious agent such as hepatitis C virus (HCV) and human immunodeficiency virus (HIV) to humans by bed bugs.^[vii]

While the risk of transmission of infectious diseases appears to be minimal, the report did identify a number of reactions, including skin reactions of varying degrees (ranging from no reaction at all, to itching and swelling, to severe reactions such as blistering and the raising of large wheals), and less frequently, systemic reactions including asthmatic and anemic reactions.

Secondary infections may also occur if care is not taken to disinfect bed bug bites, and appear to be more frequent in children, and in the elderly. Psychological distress is also a serious concern, which both causes and results from anxiety and sleep deprivation.