Bed Bugs or Something Else? The Evidence Checklist to Run Before You Pay for Treatment

Bites alone never confirm bed bugs. Not ever. Reactions vary so much between people that two adults in the same bed can wake up with one covered in welts and the other with nothing at all. The only way to know if you have bed bugs is physical evidence: live insects, cast skins, fecal spotting, or eggs. Find one of those and you have an answer worth paying to fix.

Quick Answer: How to Know If You Have Bed Bugs

You confirm bed bugs with physical evidence, not bites. Check the mattress seams and tufts, the box spring edge and the underside dust cover, and the back of the headboard. You’re looking for live insects (flat, oval, reddish-brown, apple-seed sized as adults), pale amber cast skins, and dark fecal spots that bleed into fabric like a marker dot. Any one of those confirms it. Bites alone do not.

The Evidence Ladder, Most Reliable to Least

1. Live insects — conclusive, if you identify them correctly
2. Cast skins — nearly conclusive, and they last for months
3. Fecal spotting — very strong when it passes the bleed test
4. Egg casings — strong, but hard to see without magnification
5. Blood smears on sheets — suggestive, not proof
6. Bites — not evidence of anything on their own

Work down that list in order. Most people start at the bottom, panic, and call somebody. Start at the top instead and you’ll either save yourself a few hundred dollars or walk into the appointment already knowing what you’ve got.

1. Live Insects: What They Actually Look Like

Bed bugs go through five nymph stages, called instars, and they look different at each one. This is where most homeowner IDs go wrong — people are looking for the adult in the stock photo and ignoring the five smaller versions crawling around it.

• Adult: about 4–5 mm, roughly the size and shape of an apple seed. Flat and oval when unfed, swollen and darker red after feeding. Reddish-brown. No functional wings, though it has small wing pads. Short, blunt head.
• 5th instar: about 4.5 mm, close to adult size but lighter in color.
• 3rd–4th instar: 2–3 mm, tan to light brown, visible without magnification if you know to look.
• 1st–2nd instar: 1.5–2 mm and nearly translucent straw-colored until they feed — then a dark red blob shows through the body. Easy to mistake for lint.

The tell that holds across every stage: bed bugs are flattened top to bottom, oval, and have no visible wings. They move at a steady crawl, not a scurry, and they don’t jump or fly.

The Look-Alikes That Cost People Money

• Carpet beetle larvae — probably the number one false alarm. They’re hairy with obvious bristles and a tapered, carrot-like shape, and they leave shed bristly skins. Bed bugs are smooth and have zero hair you can see. Carpet beetle bristles also cause an itchy rash in some people, which is exactly why the confusion persists.
• Bat bugs — nearly identical to bed bugs to the naked eye. The difference is the fringe hairs on the pronotum (the shield behind the head), which are longer than the eye width on a bat bug. That’s a microscope call, not a flashlight call. Bat bugs show up where bats roost in attics and wall voids, which makes them a real consideration in older homes across the Midwest, the Northeast, and the upper South. If an operator treats for bed bugs and the problem keeps coming back from the ceiling, push for a bat bug ID and an attic check.
• Spider beetles — round, humped, shiny, with long legs and long antennae. They genuinely look like a tiny spider. Bed bugs are flat; spider beetles are bulbous.
• Immature cockroaches — German cockroach nymphs are dark, fast, and have two pale stripes running down the pronotum. They’re longer than they are wide and they bolt when the light hits them. If it ran, it wasn’t a bed bug. Our guide to telling roaches apart from water bugs covers the roach side of this in detail.
• Booklice — tiny, pale, soft, and found around damp paper and cardboard. Harmless, and no relation.

2. Cast Skins

Every bed bug molts five times on the way to adulthood, and each molt leaves behind a hollow amber shell in the shape of the bug. These are gold for diagnosis, because they last for months and they don’t run away when you shine a light.

A cast skin looks like a bed bug made of cellophane — same outline, same size, but translucent, brittle, and empty. You’ll usually find them clustered in the same harborage areas as the live bugs, often mixed with fecal spotting. Under a phone camera at max zoom you can usually see the split along the back where the bug climbed out.

Important: cast skins prove there was a reproducing population. They don’t prove there still is one. If a unit was treated a few months ago, old skins may be leftovers. Live bugs and fresh spotting are what tell you it’s current.

3. Fecal Spotting and the Bleed Test

This is the single most useful thing a homeowner can check, and almost nobody knows the trick.

Bed bug fecal spots are digested blood. On fabric they’re dark brown to near-black, usually 0.5 to 1.5 mm, and they often appear in clusters or short trails along a seam rather than scattered randomly. On a hard surface like a bed frame or wall they look like someone touched it with a fine-point marker.

The bleed test: put a drop of water on a white paper towel or a cotton swab and press it gently onto the spot. Bed bug fecal matter dissolves and bleeds outward into the fabric in a rusty reddish-brown halo, because it’s digested blood. Dirt, mold, and general grime smear or flake — they don’t feather out into the fibers that way. If it bleeds, that’s a very strong positive.

Two cautions. Don’t run the bleed test on every spot you find, because you’ll destroy the evidence you want the inspector to see — test one, photograph the rest. And a spot that doesn’t bleed isn’t automatically clean; older, dried spotting can be stubborn.

Confirmed Something? Get It Routed to a Local Operator

Once you’ve got real evidence, the next call is a licensed inspection and a treatment plan. Exterminator Dispatch is a free nationwide matching service — we route your request to the independently owned, licensed local exterminator who covers your area, 24/7. Call (888) 295-0220 and describe exactly what you found and where, or check coverage on the service areas page. We route the request and set no pricing — the operator inspects, quotes, and treats.

4. Blood Smears on Sheets

Small rust-colored smears on sheets, usually where your body contacts the mattress, come from bugs being crushed while feeding or from a bite site that kept bleeding a little. They’re suggestive but weak on their own — a scratched-open bug bite of any origin, a nosebleed, or a scab can produce the same thing.

Treat blood smears as a prompt to inspect, not as a finding. What makes them meaningful is when they show up alongside fecal spotting on the same sheet or mattress seam.

5. Eggs and Egg Casings

Bed bug eggs are about 1 mm, pearly white, slightly curved, and cemented to the surface with a glue the female produces — so they don’t brush off easily. They’re typically laid in tight cracks: the piping seam of a mattress, a screw hole in a bed frame, the underside of a slat.

Hatched casings are the same shape but empty and with the cap popped off. At 1 mm you’re at the edge of naked-eye detection. A phone flashlight held at a low raking angle across the seam helps enormously — side lighting makes them cast a shadow instead of disappearing into a white mattress.

The Inspection Sequence, In Order

Do it in this order. Bed bugs concentrate within about 5 to 8 feet of where a person sleeps, so the bed is where you’ll find them 85 to 95 percent of the time. Give yourself 30 minutes, a bright flashlight, and an old credit card to run along seams.

1. Mattress seams and tufts. Run the light along every piping seam, and look inside the button tufts and any tear or tag. Start at the head end.
2. Box spring edge, then the underside dust cover. This is the highest-yield spot in the whole house and the one people skip. Stand the box spring up and look at the stapled wooden frame inside the fabric. If the dust cover is already torn, shine the light through the gap. Do not rip a sealed cover open before the inspector arrives — note it and let them do it.
3. Headboard: back face and wall mounts. Pull it off the wall. Check the back, the mounting brackets, and the screw holes. Wall-mounted headboards hide entire populations.
4. Bed frame joints. Every joint, bolt hole, slat end, and the inside of hollow tube legs.
5. Nightstand. Pull the drawers all the way out and check the seams, the drawer runners, and the underside and back of the piece.
6. Upholstered furniture you sleep in. A recliner someone naps in nightly can outrank the bed.
7. Carpet perimeter. Run the card along the tack strip edge where the carpet meets the baseboard, especially near the bed.
8. Outlet and switch plates near the bed. Look at the plate edges. Do not unscrew and probe live electrical — leave that to the operator.

What to Do With What You Find

• Bag it. A live or dead specimen goes in a zip bag or a pill bottle with a little rubbing alcohol. A piece of clear tape over the bug works too. A crushed smear on a tissue is not identifiable.
• Photograph with scale. Put a penny, a dime, or the ruler edge of a tape measure right next to it. Size is half the ID, and a photo with no scale reference is nearly useless to an inspector.
• Write down where. “Northwest corner of the box spring frame, head end” is worth far more than “in the bedroom.”
• Don’t start spraying. Over-the-counter aerosols are usually repellent, which scatters a contained population into wall voids and adjacent rooms and makes the professional job harder and more expensive.
• Don’t throw out the mattress yet. Dragging an infested mattress through the house spreads bugs down the hallway, and a replacement lands in the same infested room. Most operators would rather treat and encase it.
• Don’t move to the couch. That’s the classic mistake — it just starts a second infestation in the living room.

Why a Canine Inspection Is Used, and Where It Falls Short

Trained detection dogs can alert on live bugs and viable eggs in places a visual inspection can’t reach — inside wall voids, deep in upholstery, behind baseboards. In a large building or a low-level infestation, that’s genuinely valuable.

The limits are real, though, and an honest operator will tell you about them:

• Accuracy depends heavily on the individual handler and how recently the team was certified. Field performance is usually well below the numbers quoted from controlled trials.
• Dogs can alert on dead bugs, old cast skins, and empty egg casings — residual odor from an infestation that’s already gone.
• Handler cueing is a documented problem when the handler knows which room is “supposed” to be positive.
• A canine alert is a lead, not a confirmation. It should always be followed by a visual inspection that finds actual evidence at the alert site.

If a company’s process is “the dog alerted, here’s your quote” with nothing physical produced, ask them to show you what they found.

Not Sure What You’re Looking At? Call It In

Describing it accurately gets you a better answer fast. Have your photos, the size reference, and the exact locations ready, then call (888) 295-0220 for 24/7 dispatch to an independently owned, licensed local exterminator in your area. If your specimen turned out to be fast-moving and striped instead, start with the roach identification guide. Exterminator Dispatch is a free nationwide referral service and sets no pricing.

What a Legitimate Operator’s Inspection Should Include

When the licensed operator you’re matched with arrives, a real bed bug inspection looks like this:

• They ask questions first: when bites started, travel history, recent secondhand furniture, whether neighbors have had issues in a multi-unit building.
• They strip the bed and inspect the mattress and box spring themselves, including cutting or lifting the dust cover.
• They pull the headboard off the wall and move furniture. An inspector who doesn’t move anything didn’t inspect.
• They inspect adjacent rooms and any other sleeping surface, not just the one you pointed at.
• They show you what they found and tell you what stage and how widespread it looks.
• They explain the treatment approach — heat, chemical, or both — and why, along with the prep you’ll need to do and the follow-up schedule.
• In a multi-unit building, they raise the question of adjacent units, because treating one apartment in isolation often fails.

For context on pricing, licensed operators commonly charge roughly $300 to $600 per room for conventional chemical treatment and about $1,000 to $2,500 or more for whole-home heat treatment, with inspections often running $0 to $150 depending on the market and whether it’s credited toward service. Those are operator-set numbers and vary a lot by region and home size — a dense Northeast multi-unit building and a large single-family home in the Mountain West price very differently.

Which is exactly why you confirm first. A confirmed infestation is worth that money. A carpet beetle problem is not.

Frequently Asked Questions

How do you know if you have bed bugs or something else?

You confirm with physical evidence, never with bites. Look for live insects that are flat, oval, wingless and reddish-brown, pale amber cast skins, and dark fecal spots that bleed reddish-brown into fabric when touched with a damp swab. Carpet beetle larvae (hairy and bristly), spider beetles (round and humped), and German cockroach nymphs (fast and striped) are the common look-alikes.

Can you have bed bugs without seeing any bites?

Yes. A large share of people show no visible reaction to bed bug bites at all, and reactions often take days to appear. That’s why the absence of bites doesn’t rule anything out, and why bite patterns are unreliable in either direction. Inspect for physical evidence regardless of what your skin is doing.

What is the fastest way to check for bed bugs?

Check the box spring first. Stand it on edge and inspect the stapled wooden frame under the fabric dust cover, then work the mattress piping seams and the back of the headboard. That sequence covers the highest-probability harborage in about 15 minutes and finds most infestations that are present.

Do bed bug fecal stains wash out?

Often, yes, on washable fabrics laundered hot with detergent, though older set stains can persist. That’s useful for sheets but irrelevant to diagnosis. Don’t launder the evidence before an inspection — photograph the spotting on the mattress and box spring and leave it for the inspector to see.

Are bed bug dogs accurate?

Detection dogs are useful for narrowing a search, especially in large or multi-unit buildings, but real-world accuracy varies a lot by handler and training. Dogs can also alert on dead bugs and old casings from a resolved infestation. Treat an alert as a lead that must be confirmed visually, not as proof on its own.

Should I throw away my mattress if I have bed bugs?

Usually not. Moving an infested mattress through the home spreads bugs along the way, and a new mattress placed in an untreated room gets infested again. Most licensed operators prefer to treat the mattress and seal it in a certified bed bug encasement, which traps anything inside and makes future inspections much easier.

About Exterminator Dispatch

Exterminator Dispatch is a free nationwide referral service. We match homeowners with independently owned, licensed local exterminators. We are not a pest control company, we don’t perform treatments, and we don’t set pricing — the operator inspects, quotes, and treats.