Bug That Looks Like a Ladybug
Nine times out of ten in autumn it is an Asian lady beetle, which is a ladybug — just not a native one, and unlike the natives it does bite. The white M behind the head settles it in a second.
The plate behind the head decides it
Spot count is useless: the Asian lady beetle ranges from no spots to nineteen, which covers every native pattern. The pronotum — the plate between the head and the wing cases — does not lie.
- White M or W shape on a black-and-white plate — Asian lady beetle.
- Plain black-and-white plate with no M — a native ladybug.
- Under 3 mm and mottled rather than spotted — carpet beetle, not a ladybug at all.
- Yellow-green with twelve black spots, on garden plants — spotted cucumber beetle.
- Metallic and elongated rather than domed — a leaf beetle of some kind.
- Swarming a sunny wall in autumn by the hundred — Asian lady beetle, every time.
What it probably is
- Asian Lady BeetleHarmonia axyridisTake care
- LadybugCoccinella septempunctataHarmless
- Carpet BeetleAnthrenus verbasciTake care
- Spotted cucumber beetleNo record yet
- Asian Lady Beetle. The white M behind the head, plus autumn swarming and a yellow staining fluid when disturbed. This is the one that bites.
- Ladybug. No M marking, and it does not gather in numbers on your house. Harmless and worth keeping.
- Carpet Beetle. Far smaller — 2–3 mm against 6–8 — and patterned in mottled scales rather than clean spots. Found at windows, not on plants.
- Spotted cucumber beetle. Yellow-green rather than red or orange, elongated rather than domed, with twelve black spots. A garden pest, not a house invader.
If you still can’t tell
Photograph it from directly above with the flash on and zoom into the plate behind the head. That is the whole identification, and it is the one detail a phone can usually resolve. If the animal is too small for the plate to be visible at all, it is almost certainly a carpet beetle rather than any kind of ladybug — size alone rules the group out.
Common questions
Do ladybugs bite?
Native ones essentially do not. Asian lady beetles do — a brief nip that occasionally breaks skin, usually when they are looking for moisture. If something ladybug-shaped bit you, that is which.
Why are hundreds on my wall?
Asian lady beetles overwinter communally and treat a warm pale sunlit wall as a cliff face. Native ladybugs do not do this, so the behaviour alone is close to diagnostic.
What is the yellow stain they leave?
Their own blood, released from the leg joints as a defence. It smells strongly and stains light paint and fabric, which is why vacuuming beats squashing.
Is it true you can age a ladybug by its spots?
No. Spot count is fixed by species, not by age. It is the most persistent piece of ladybug folklore and it is simply wrong.
Or just photograph it
If none of these fit, the identifier will take a photo and give you a species, a danger verdict and what it is commonly mistaken for. It says when a photograph cannot settle something rather than guessing — what it can and can’t do.
Where this was checked
- NC State Extension — Multicolored Asian Lady Beetle in the Landscape checked 2026-07-30
- Ohio State University Extension (Ohioline) — Lady Beetles checked 2026-07-30
Last reviewed 2026-07-30.