Tiny black bugs in a bed are most often black or varied carpet beetles, fleas brought in by a pet, or, less often, bed bugs. Bed bugs themselves are brown to reddish, not black, but the black specks they leave on sheets are their droppings. Watch how the bug moves: carpet beetles crawl slowly and are round, fleas jump, and bed bugs are flat, oval and apple-seed shaped.
The steps below help you work out which one you have before you buy sprays or throw out a mattress.
The usual suspects at a glance #
| Bug | Size | Shape and color | How it moves | Bites? |
|---|---|---|---|---|
| Black carpet beetle (adult) | About 1/8 inch | Oval, shiny black to dark brown, hard shell | Slow crawl, can fly | No |
| Varied carpet beetle (adult) | 1/10 to 1/8 inch | Round, mottled white, brown and yellow | Slow crawl, can fly | No |
| Carpet beetle larva | Slightly longer than adult | Fuzzy, striped brown, tufted “tail” | Slow crawl | No, but hairs can irritate skin |
| Flea | A few millimeters | Narrow, flattened side to side, dark reddish-brown | Jumps | Yes |
| Bed bug (adult) | 5 to 7 mm | Flat, oval, brown; reddish and swollen after feeding | Crawls, can’t jump or fly | Yes |
| Bed bug (nymph) | Smaller | Translucent or whitish-yellow, red after feeding | Crawls | Yes |
Carpet beetles: the most likely answer #
Carpet beetles are the bugs people most often mistake for bed bugs, and they’re the most common “tiny black bug” in beds. UC IPM describes the adults as about 1/10 to 1/8 inch long with rounded bodies and short antennae. The black carpet beetle is shiny black and dark brown. The varied carpet beetle is covered in a pattern of white, brown and dark yellow scales that can look dark from a distance.
Adults feed on pollen and nectar, and they usually come indoors on cut flowers or through windows. Indoors you’ll find them on windowsills, drapes and window panes, and they sometimes crawl onto bedding. They don’t bite.
Their larvae are the real problem. They look like tiny fuzzy caterpillars with light and dark brown stripes, and they eat wool, silk, feathers, fur, hair and lint, which is why they live in down comforters, wool blankets, under the bed and along carpet edges. They leave behind brown, bristly shed skins, which is a good sign that you have carpet beetles rather than something that bites. Some people get itchy red bumps from contact with the larval hairs, which is one reason carpet beetles get blamed for “bites.”
What to do: vacuum the mattress, bed frame, carpet edges and under furniture, wash bedding in hot water, check wool and down items, and clean window sills. UC IPM puts sanitation first and only suggests an insecticide labeled for carpet beetles for heavy infestations.
Fleas: if the bug jumps #
A tiny dark bug that springs out of sight when you reach for it is almost certainly a flea. Fleas are narrow, flattened from side to side, and reddish-brown to nearly black. The CDC notes that fleas prefer animal hosts and bite people when an animal isn’t available, which is why flea problems often flare after a pet has been away or a previous owner’s pet has moved out.
A quick test: put the black specks from the bedding on a damp white paper towel. Flea droppings are digested blood and will smear reddish-brown.
What to do: treat every pet in the house with a flea product your veterinarian recommends, wash pet bedding and your own bedding in hot water, and vacuum daily for a couple of weeks. Flea eggs and larvae live in carpets and pet beds, so treating only the bed won’t solve it.
Bed bugs: if the bug is flat, oval and brown #
Bed bugs aren’t truly black, but a well-fed adult or a crushed one on a dark sheet can look dark. The EPA describes adults as about the size of an apple seed (5 to 7 mm), long and brown with a flat, oval body when unfed, and balloon-like and reddish-brown after feeding. Young nymphs are smaller, translucent or whitish-yellow, and can be almost invisible until they eat.
What people usually see first is evidence, not bugs. The EPA lists:
- Rusty or reddish stains on sheets or mattresses from crushed bed bugs
- Dark spots about the size of a period that bleed into the fabric like a marker (droppings)
- Tiny pale eggs, eggshells and shed skins
- Live bugs in mattress seams, box spring crevices, headboard cracks and furniture joints
Bites alone don’t prove bed bugs. The EPA calls bites “a poor indicator” because they look like many other bites and rashes, and the University of Kentucky notes that about 30% of people don’t react to bed bug bites at all.
What to do: don’t use foggers (“bug bombs”), which the University of Kentucky calls ineffective and dangerous. Put bedding through a hot dryer, encase the mattress and box spring, and contact a professional or your extension office to confirm the ID before paying for treatment. Our bed bug vs carpet beetle guide has side-by-side details.
Other things that turn up in beds #
- Bat bugs and swallow bugs look almost identical to bed bugs and are linked to bats or birds nesting in the attic or walls. Only a close look under magnification separates them.
- Spider beetles are tiny, round, reddish-brown to dark beetles with long legs that live on stored food and debris.
- Springtails are tiny, dark and jump like fleas, but they need damp conditions and don’t bite. They usually point to a moisture problem nearby.
- Ticks can drop off a pet or person onto bedding. They have eight legs as adults and a flat, teardrop shape. If you find one attached to skin, follow the CDC’s removal steps.
How to identify the bug for sure #
- Catch one on clear tape or in a zip bag. A specimen beats a description.
- Photograph it close up in good light, from above and from the side. Our guide to photographing a bug for identification covers the details that matter.
- Check it with an app. Insect Identity can tell the bed bug, black carpet beetle, varied carpet beetle and cat flea apart from a single photo. It shows the best match with a confidence score and four runners-up, runs on your phone with no internet, and never uploads the picture. It doesn’t know bat bugs, spider beetles or springtails, and it’s weaker on tiny nymphs, so a low score is a signal to get a person’s opinion.
- Confirm bed bugs with a professional before any treatment. Your county Cooperative Extension office can often identify a specimen.
Frequently asked questions #
What are tiny black bugs in my bed that aren’t bed bugs? #
Carpet beetles are the most common answer, followed by fleas. Carpet beetles are round, hard-shelled and slow; fleas are narrow and jump. Spider beetles and springtails turn up occasionally.
Do carpet beetles bite? #
No. Carpet beetles don’t bite people, but the bristly hairs on their larvae can cause an itchy rash in some people, which is easily mistaken for bites. If you’re getting bites and can only find carpet beetles, keep looking for fleas or bed bugs too.
What do bed bug droppings look like? #
Small dark spots about the size of a printed period, often in clusters along mattress seams. They soak into fabric and smear like marker ink when you wipe them with a damp cloth.
Can tiny black bugs in bed come from my dog or cat? #
Yes. Fleas travel on pets and fall off where the animal sleeps, including your bed. If the bugs jump and your pet has been scratching, treat the pet and its bedding first.