"Something is biting me at night" is one of the most common — and most frustrating — pest complaints. You wake up with itchy welts but can't find any bugs. Before spending money on treatment, you need a diagnosis. Many "mystery bites" aren't bites at all. And when they are, identifying the source determines the treatment.
Dermatitis and skin reactions cause welts that look identical to insect bites. New laundry detergent, fabric softener, body wash, or bedding materials can trigger contact dermatitis. Dry winter skin causes itchy bumps. Dust mite allergens in bedding cause allergic skin reactions without any actual biting. If you can't find a single bug or any evidence after thorough inspection, a dermatologist may be more helpful than an exterminator.
Bed bugs are the #1 cause of actual nighttime biting. Inspect: mattress seams and piping, headboard joints and behind the headboard, box spring folds and stapled fabric, nightstand drawers and undersides, and outlet covers on bedroom walls.
What to look for: Dark fecal spots (tiny ink-like dots), shed skins (translucent), live bugs (apple-seed sized, flat, brown), and blood spots on sheets. Use a flashlight and credit card to probe seams. See our complete bed bug inspection guide.
Interceptor test: Place bed bug interceptor traps under all four bed legs. If bed bugs are feeding nightly, interceptors catch them within 1–2 weeks — providing conclusive evidence.
If you have pets, fleas are the second most likely cause. Flea bites concentrate on lower legs and ankles (ground-level feeding), unlike bed bug bites which appear on any exposed skin. Check pets for flea dirt (black specks in fur that turn red when wet) and check carpet near pet sleeping areas with a white sock test — shuffle across the carpet in white socks and check for jumping specks.
Bird mites: If a bird nest was recently removed or abandoned near your bedroom window, bird mites may be entering seeking new hosts. Bites appear as intense itchy clusters.
Rodent mites: If you've had a recent mouse problem, tropical rat mites and house mouse mites may be biting after their rodent host was removed or died.
Mosquitoes: A single mosquito trapped in the bedroom can deliver multiple bites per night. Check for mosquitoes resting on walls and ceilings, especially behind furniture.
Bat bugs: If you've had or currently have bats in the attic, bat bugs (nearly identical to bed bugs) can migrate into bedrooms through wall voids.