Orange and Black Bug Identification: 7 Common Culprits

The orange and black bug most often found in and around houses is the boxelder bug: a black bug about 1/2 inch long with orange or red markings, including three stripes just behind the head (University of Minnesota Extension). The second most common is the multicolored Asian lady beetle. InsectIdentification.org lists 389 black and orange insects in North America, so the place, the season and the shape narrow it down faster than colour:

• Clusters on a sunny south or west wall in late summer and fall: boxelder bugs (UMN).
• Round beetles gathering on the house on warm afternoons from early October: Asian lady beetles (Penn State Extension).
• Tiny red specks crawling indoors in spring or fall: clover mites (UMN).
• Small round beetles on a window sill, with damaged wool nearby: carpet beetles (UC IPM).
• Groups on milkweed plants outdoors: large milkweed bugs (Wikipedia).
• A fuzzy, wingless, ant-like insect: a velvet ant, which is a wasp (Garden Betty).
• A slender wasp with long dangling legs: a paper wasp; some are golden brown with yellow or red patches (UC IPM).

• Boxelder bug: about 1/2 inch, black with orange or red markings and three stripes behind the head. Newly hatched nymphs are bright red and turn red and black as they grow (UMN). They feed on boxelder trees in summer (GardenTech).
• Multicolored Asian lady beetle: 7 mm long and 5.5 mm wide, extremely variable; most have red or orange wing covers with up to 18 black spots, some are black with orange marks. Look for a white plate behind the head with a black W (Penn State).
• Large milkweed bug: 11 to 12 mm, red-orange with a black X-shaped pattern on the wings; feeds on milkweed seeds (Wikipedia).
• Clover mite: slightly smaller than a pin head, reddish or reddish-brown, with eight legs. It is a mite, not an insect (UMN).
• Carpet beetles: varied carpet beetles are 1/10 to 1/8 inch, black with an irregular pattern of white, brown and dark yellow scales; black carpet beetles are 1/8 to 3/16 inch, shiny black and dark brown (UC IPM).
• Velvet ant: a hairy, wingless female wasp; the red and black species called the cow killer has an extremely painful sting (Garden Betty). Do not pick one up.
• Paper wasps: about 1 inch, slender, golden brown or darker with yellow or red patches (UC IPM).

• Boxelder bugs: UMN says they do not bite or harm people; GardenTech says they rarely bite. Their droppings can stain walls, curtains and other surfaces (UMN).
• Asian lady beetles: Penn State says they occasionally bite, from slightly annoying to painful. When disturbed they release a smelly yellow fluid from their leg joints that can spot walls, and indoor infestations have been linked to allergic symptoms including asthma and facial swelling.
• Clover mites: feed on grass and do not bite people or animals. Crushed mites leave rusty or blood-red spots (UMN).
• Carpet beetles: the adults feed on pollen and nectar outdoors; the larvae damage wool, silk, leather, fur and feathers (UC IPM).
• Velvet ants and paper wasps: both can sting. Paper wasps rarely sting people (UC IPM).

If a bite or sting is followed by swelling of the face or throat, trouble breathing or a spreading rash, get medical care.

Not in itself. UC IPM describes carpet beetles in homes, warehouses and museums wherever wool, yarn, fur and feathers are stored, and says adults often fly in from flowers outside and are drawn to sunlight, which is why they end up on window sills. Cleaning still matters: UC IPM notes food and perspiration stains on fabric attract carpet beetles, and larvae also eat pet hair, so regular vacuuming and washing stored wool removes their food. The larvae leave brown, bristly cast skins and no webbing, which separates them from clothes moths.

• Vacuum them. UMN recommends a vacuum or a broom and dust pan for boxelder bugs, and says indoor pesticides are not recommended because the bugs do not live indoors more than a few days. Penn State calls vacuuming the most efficient way to remove lady beetle clusters.
• Seal before they arrive. Caulk cracks around windows, doors and siding (Penn State); UMN advises sealing before late August for boxelder bugs.
• Clover mites: vacuum or wipe them with a damp cloth rather than crushing them, and keep a strip of clean, bare soil 18 to 24 inches wide around the foundation (UMN).
• Carpet beetles: find and clean the wool, fur or feathers the larvae are feeding on (UC IPM).

Take one photo from directly above and one from the side, with a coin for scale. For lady beetles, make sure the plate behind the head is visible; for boxelder bugs, the three stripes behind the head. InsectLens names the bug from the photo.

Research and drafting for this page used AI assistance. Every figure, date and quotation was then checked line by line against the sources listed at the bottom of the page, each of which was opened while writing. Nothing here is a diagnosis. If a bite, sting or contact with an insect is followed by trouble breathing, swelling of the face or throat, spreading redness, fever or any symptom that worries you, get medical care; in the United States Poison Help (1-800-222-1222) is free and open 24 hours a day.