How to check for bed bugs and read what you find

Strip the bed and move a bright flashlight slowly along the piping and seams of the mattress and box spring, then into the joints of the frame and headboard, the places bed bugs gather first. You are looking for physical evidence such as live bugs, pale shed skins, eggs about 1 mm long and dark spots that bleed into fabric, because EPA calls bites a poor indicator and some people never react to them.

Bite marks can also arrive late. In some people they take as long as 14 days to show.

One suspect bug found tonight is not a medical emergency, since bed bugs are not known to spread disease. Treat it as a sample to get identified. What each piece of evidence looks like up close is covered in the signs of bed bugs, shown one by one; what follows is how to run the check and how far to trust the result.

A flashlight, a thin card and a jar with a lid

Because bed bugs are only about as thick as a credit card, any crack that would hold a card can hide one, so the check depends on strong light and something thin enough to slide into a seam. The kit comes from a homeowner guide written by Michigan State University Extension and published by Georgia’s Department of Public Health:

• A bright flashlight and a magnifying glass
• A long, thin probe such as a putty knife, playing card or nail file
• A vacuum with a crevice tool, plus gloves and paper towels
• A notebook for every room and spot where something turns up, to share with whoever treats the home
• A small jar of rubbing alcohol with a tight lid

Penn State’s insect identification lab accepts specimens preserved in rubbing alcohol, which is why the jar belongs in the kit.

Start at the mattress seams, then work outward

Before you lift anything, peel the bedding back slowly and look at the sheet corners and pillowcases for rusty smears, which come from bugs that were crushed. Then work in this order:

1. Mattress, top and underside. Run the light along the piping, seams, tufts, tags and handles. Holding the beam low so it rakes across the fabric makes eggs and newly hatched bugs easier to see.
2. Box spring. Check the corners and the thin dust cover underneath, where a fabric strap can hold adults, skins, droppings and eggs.
3. Frame and headboard. Slide your card into the joints and screw holes, and look behind the headboard.
4. Nightstands. Pull each drawer all the way out and check its inside and joints, down to the screw holes.
5. The rest of the room, out to about 15 to 20 feet from the bed: baseboards, curtain folds, picture frames, upholstered chairs and loose wallpaper.

The order follows the bugs. They can travel more than 100 feet in a night yet tend to live within 8 feet of where people sleep, so the bed comes first.

Do one pass in daylight and another after dark. Bed bugs are active mainly at night and peak before dawn, though a hungry one will seek a host in full daylight. The less obvious hiding places, from electrical receptacles to the line where wall meets ceiling, are mapped in where bed bugs hide, room by room.

Safety: Check outlet and switch faceplates by eye only, and never push a card, probe or tool into areas with wires. Leave the cover plates on. Don’t spray, dust or set off a fogger during the check, since foggers can’t reach the cracks where bed bugs hide and can drive them into other rooms or apartments.

Is it a bed bug or something that looks like one?

EPA warns that carpet beetles can be mistaken for bed bugs, and a wrong call gives an infestation more time to spread. Spider beetles and newly hatched cockroaches get confused with them too, as the lookalike panel in Sarasota County’s health guide shows. An adult is flat, oval and rusty red, about the size of an apple seed, while a newly hatched one is pale tan and about the size of a poppy seed. Photos of every stage are in what bed bugs look like from egg to adult.

Bat bugs are the harder case, because they are close relatives that can also bite people. Under a hand lens, the hairs fringing the body just behind a bat bug’s head are longer than its eye is wide, and on bed bugs those hairs are shorter (Colorado State University Extension). Bat bugs are found near roosting bats rather than around beds, and because their treatment differs, where you found the bug becomes part of the identification.

Dark spots are the easiest sign to test at home. Bed bug droppings are about the size of a printed period, and on fabric they bleed outward like a marker. Rub one with a dry fingertip and it stays put. Wipe it with a damp rag and it smears, because the spots are partly digested blood.

A clean check isn’t the same as no bed bugs

You can have bed bugs and find none of them. In a Rutgers survey of 2,372 New Jersey apartments, brief visual inspections detected 72% of infestations, interceptor traps under bed and sofa legs detected 89%, and 49% of the infested homes belonged to residents who didn’t know they had bed bugs (Journal of Medical Entomology study). In the same survey, 32% of residents who had lived with bed bugs reported no bite symptoms.

So if your search turns up nothing but the bites or the worry continue, keep looking or have the home inspected before anyone treats. Pull the bed away from the wall and set interceptors under every leg of the bed and the sofa. Watching only beds or only sofas would have missed 15% to 28% of the infestations in that survey, and its traps were checked 10 to 17 days after they went down. Published catch counts for each design are compared in which bed bug interceptors catch the most.

After that, a look at the mattress seams each time you wash the bedding keeps the check routine, especially if you work in or visit other people’s homes.

Dog inspections and what to ask

When Rutgers researchers tested 11 commercial dog-and-handler teams in naturally infested apartments, the teams found 44% of infestations on average. Individual teams ranged from 10% to 100%, and false alerts ran at 15%, even though every handler believed their dog found 95% or more (Journal of Economic Entomology study). If you book a canine inspection, ask the company for its state pest control license number, and whether the handler will show you a live bug, shed skin or egg at each spot the dog marks before treatment is scheduled. Finding a bug is the way to know for sure.

Get any suspect bug identified before you treat

If the flashlight turns up a bug or a cluster of spots, collect before you clean. Drop the bug into the alcohol jar, photograph the spots where they sit, and note the room and the exact place. Then take the sample to your county extension office or local environmental health office, where trained staff can confirm what it is, and ask them whether it is a bed bug or a bat bug. Skip matching it against online photos, since a picture labeled that way may show something else.

For renters: Report suspected bed bugs to your landlord or building manager and don’t apply insecticides yourself. How fast a landlord must respond, and who pays, depend on state and city law and on your lease. Georgia, for one, has no bed bug law, so any bed bug terms there come from the rental agreement, and tenants who get no response can turn to city code enforcement. The rules on who handles bed bugs in an apartment go further.

Once the sample is confirmed, the notes from your inspection become the treatment map. Georgia’s guide recommends hiring a licensed pest management company and asking it for a written integrated pest management plan that names every method and product. If you are weighing treatment yourself first, the full plan to get rid of bed bugs starts from the spots you recorded tonight.