Signs of Bed Bug Activity
Recognizing The Signs of Bed Bugs

When bed bugs are suspected, sleeping and resting areas should be thoroughly inspected. Keep in mind that bed bugs (especially nymphs and eggs) can fit into the tiniest cracks and crevices. Rule of Thumb: “If a business card could fit so can a bed bug”. Bed bugs are very elusive critters. This makes detecting the presence of bed bugs–particularly in the early stage–very difficult even for pest professionals. Hence the introduction of bed bug canine detecting dogs. On the other hand, bed bugs do not have a way of cleaning up after themselves. They eventually leave telltale signs behind that are dead giveaways of their existence. In any event, here are some things to look for if you suspect that you have bed bugs.

Bed Bug Bites

Reactions to bed bug bites vary from person to person–even two people sharing the same bed. Bites are very similar to mosquito bites and other blood sucking insects, however, bed bug bites are usually patterned in a row (½” to an inch apart) or in clusters–similar to a rash-like appearance. In most cases, bites consist of raised, red bumps, swelling, serious rashes, flat welts even blisters and are often accompanied by intense itching (as a result of an allergic reaction to the anesthesia contained in the saliva that bed bugs inject into the blood of its victims). Itching may not start until minutes, hours even days after the bite. Bites may become immediately visible or take days to appear. 20-30% of all people exhibits no sign of having been bitten by a bed bug whatsoever—greatly increasing the difficulty of confirming the existence of infestations until it’s in the moderate to severe stage. Also, because of the disparity in bite reactions and appearances, bed bug bites can rarely be identified by the appearance alone. That’s why it is important to obtain a specimen (dead or alive) or look for other telltale signs as bites on the skin are poor indicators of a bed bug infestation as bed bug bites can look like bites from other insects, rashes–even hives.

Live Bed Bugs

Bed bugs look vastly different during each stage of development. For instance, nymphs (aka: first instar or first hatchling) have similar heads, mouth-parts and bodies as adult bed bugs, but on a smaller scale and their coloration is very different. They are tan in color and their bodies are translucent. The bed bugs at the bottom of the picture on the left, is an adult male. Adult bed bugs are reddish-brown, flightless insects around 1/4″ long. They’re flat when unfed and football-shaped when engorged with blood. When a bed bug molt to adult stage, they are sometimes waxy in appearance and more orange in color. To give an a size reference, the adult male bed bug at the bottom of the picture is next to grains of rice and there is an egg located to the left and right of the bed bug.

Dead Bed Bugs/Bed Bug Castings

Bed bugs go through five stages of development before reaching maturity. Bed bugs will molt (shed or cast its skin) once during each stage of development leaving an amber-color, shell of itself behind. Bed bugs must take a blood meal in order to advance to another stage of development. Shed skin or casing can be found in bed bug hiding places.


Picture Taken by: Dr. Harold Harlan of Bed bug eggs are visible to the naked eye. They are very small (approximately 1/32 of an inch long); milky-white in color, cylindrical in shape (one end rounded the other flat, hatched-like). When the first instar emerges, it emerges from the flat side. Hatched eggs appear hollow and will have the flat, hatch top like end opened (as seen the picture on the left). Eggs can hatch in a little as 3-5 days in optimal temperatures. Eggs are usually found in clusters in cracks and crevices and on rough surfaces. Eggs are coated with a sticky substance which adheres rather well to the surface where they are laid. Because of this, it is doubtful that eggs of any significant number can be successfully vacuumed. As the first in-stars emerge from egg capsules, the capsules become dry, hard, yellow in color and are easier to be removed with a vacuum cleaner from surfaces they were adhered to than if they were viable eggs

Fecal Spots of Fecal Stains

Picture Taken by: Dr. Harold Harlan of Beg bugs excrete digested blood as fecal liquid that produces spots or stains. Fecal stains may be found where bed bugs travel and hide. Because of this, fecal stains cold be the most prevalent sign of bed bug activity. Fecal spots or excrement look like brownish-black bumps on hard surfaces (like in the picture above) or may bleed on fabric like a marker would (like in picture to the left). Fecal stains on hard surfaces will run when sprayed with water and fecal stains on soft surfaces, i.e., sheets, will smear when sprayed or wiped with a damp cloth. You may also find blood stains/smears on the bedding and mattress from bed bugs being crushed.