If you woke up with a few new red welts and you’re trying to figure out what bit you, here’s the field-tested decision tree.
Look at the pattern
Bed bugs bite in a line. Three or four welts, more or less in a straight line on exposed skin — usually arms, shoulders, neck, sometimes lower legs. The line happens because the bug starts feeding, gets disturbed (you shift in sleep), moves an inch, starts again, gets disturbed, moves again. Pest control entomologists sometimes call this “breakfast, lunch, dinner.”
Mosquitoes bite in scatter. Random spots, no pattern. A welt on the left ankle, one on the right elbow, one on the neck. Each was a separate landing.
Fleas bite in clusters. Three to six welts close together, usually on the lower legs (ankles, calves). Fleas live in carpet, furniture, or pet bedding and hop short distances to feed — so the bites cluster where you were sitting or sleeping with your legs exposed.
Pattern alone gets you 80% of the way there.
Look at the timing
Bed bugs bite at night. You discover them in the morning. Bed bugs are nocturnal, hide during the day in mattress seams and headboard joints, and only emerge to feed when the host (you) is still.
Mosquitoes bite when they’re active, which in Lakeland is dusk through early morning for Culex species and daytime for Aedes. If you got bitten while reading on the patio at 7 p.m. — mosquito.
Fleas bite anytime, but most often when you sit down on infested furniture or sleep on infested bedding. Pet owners with active flea infestations notice clusters appearing within minutes of sitting on the couch.
Look at the welt itself
Bed bug welts are flat or slightly raised, red, itchy starting hours after the bite (the saliva is anesthetic, so you don’t feel the bite happen). Welts can persist 2–7 days.
Mosquito welts are domed, immediate itch (you usually feel the bite). Persist 1–3 days.
Flea welts are tiny dots with a red halo, immediate intense itch. Small but cluster pattern makes them obvious.
The 30-second confirmation test
If you suspect bed bugs:
- Pull back the corner of your fitted sheet.
- Look at the mattress seam — the welt of fabric where the top meets the side.
- Check for: tiny brown specks (fecal staining), translucent flecks the size of an apple seed (shed exoskeletons), or live bugs (flat, reddish-brown, the size of a pinhead).
- Check the same on the box-spring tag and the headboard joints.
Find any of those? Bed bugs are confirmed. Don’t vacuum yet — the evidence is useful for the inspection.
If you suspect fleas: check the pet first. Run a fine-toothed comb through the pet’s fur over a white paper towel. Black specks that turn red when you dampen them are flea feces (digested blood). Confirms fleas.
If you suspect mosquitoes: it’s mosquitoes.
What to do next
Bed bug confirmation — call us. Full scope on our bed-bug treatment page. Don’t bag your bedding yet; we want to see the harborage zones intact.
Flea confirmation — treat the pet first (vet-grade flea preventive), wash all pet bedding hot, vacuum carpets thoroughly, and book a one-time pest visit. Pest Control covers indoor flea treatment.
Mosquito bites — those are an outdoor problem. Recurring property-level treatment is the move. Mosquito timing in Central Florida →
Part of the Lakeland Pest Pros Pest Library.
