A red or reddish bug with wings inside your home is most likely one of a handful of common species: boxelder bugs, Asian lady beetles, red flour beetles, or Indian meal moths. Which one you’re dealing with depends on the bug’s size, where you found it, and what time of year it showed up. Here’s how to figure out exactly what’s sharing your space.
Boxelder Bugs
Boxelder bugs are one of the most common red-and-black winged insects that turn up indoors. Adults are about half an inch long with black bodies marked by distinctive red lines: one red line on each side of the body, a diagonal red line on each wing, and three red lines on the section just behind the head. From a distance, they look like a narrow, flat black bug outlined in red.
These bugs start migrating indoors in August and September, seeking sheltered spots to ride out the winter. They favor south-facing walls (which catch the most sun) and squeeze into window frames, attics, and gaps around doors. On warm winter days, they sometimes emerge briefly inside your home, which is why you might spot a few wandering across a sunny wall in January. They don’t bite, don’t eat your food, and don’t damage structures. They’re purely a nuisance, and vacuuming them up is the simplest fix.
Asian Lady Beetles
If the bug looks like a ladybug but seems slightly too large, too orange, or too aggressive about getting inside, it’s probably an Asian lady beetle. Adults are oval, dome-shaped, and about a quarter inch long. Their color ranges from tan to orange to deep red, and they may have many black spots, a few faint ones, or none at all. The best way to tell them apart from native ladybugs is a small dark marking shaped like an “M” or “W” on the whitish area just behind the head.
Like boxelder bugs, Asian lady beetles swarm buildings in fall (September through November) looking for winter shelter. They pile into attics, wall cavities, and cracks around window frames, sometimes in large numbers. When disturbed, they secrete a yellowish, foul-smelling fluid from their leg joints that can stain light-colored surfaces like curtains or walls. This defensive chemical is the main reason they’re more annoying than a regular ladybug. They can also give a mild pinch-like bite, though it rarely causes anything more than brief irritation.
Red Flour Beetles
If the red bug is tiny and you found it in your kitchen or pantry, you’re likely looking at a red flour beetle. These are small, about one-eighth of an inch long, reddish-brown, and capable of flight (unlike the nearly identical confused flour beetle, which can’t fly). They infest stored foods like flour, cereal, crackers, cake mixes, spices, dried fruit, chocolate, and pet food.
Signs of an infestation include a grayish tint to affected food products and a noticeable unpleasant odor when you open the container. Their presence also encourages mold growth. Red flour beetles can’t chew through intact grain kernels, so they target products that are already processed or damaged. If you find them, check every dry-goods container in your pantry. Discard anything infested, and store remaining items in airtight containers.
Indian Meal Moths
Another pantry pest with reddish coloring is the Indian meal moth, which is about five-eighths of an inch long. The outer two-thirds of each wing is a coppery-red color, while the portion closest to the body is pale gray. If you see small moths fluttering around your kitchen, especially near the ceiling or around light fixtures, this is the most likely culprit. Like red flour beetles, they infest stored grain products and dried foods.
Winged Ants and Termite Swarmers
Some species of winged ants are reddish-brown, and termite swarmers can also appear dark reddish depending on the species. Both produce winged reproductive adults that emerge in swarms, often indoors during spring or after rain. If you’re seeing a group of small winged insects suddenly appear near a window or light source, it’s worth knowing the difference.
Three features separate them. Ants have elbowed (bent) antennae, a thin pinched waist, and two pairs of wings where the front pair is noticeably longer than the back pair. Termites have straight antennae, a thick waist with no pinch, and two pairs of wings that are the same length. This distinction matters because termite swarmers inside your home signal an active colony that could be damaging your structure, while a few winged ants are usually less concerning.
One Bug Worth Taking Seriously: Kissing Bugs
Most red-marked winged bugs indoors are harmless, but kissing bugs are an exception worth knowing about. Found mainly in the southern United States, they’re dark brown or black with red, orange, or yellow stripes around the edges of their bodies. They have a distinctive cone-shaped head, thin antennae, and thin legs. They’re roughly three-quarters of an inch to over an inch long.
Kissing bugs feed on blood, typically biting people at night around the face. Their bites are usually painless, so you may not notice. The concern is Chagas disease: kissing bugs can carry a parasite in their feces that enters the body through the bite wound or mucous membranes. No other insect transmits this parasite. Many bugs look similar to kissing bugs, though. Plant-feeding insects like leaf-footed bugs and wheel bugs share a similar body shape but tend to have painful defensive bites rather than the stealthy, painless feeding style of a kissing bug. If you think you’ve found one, Texas A&M’s kissing bug identification program accepts photo submissions.
How to Keep Winged Bugs Out
For overwintering pests like boxelder bugs and Asian lady beetles, the key is sealing entry points before fall arrives. Caulk cracks around windows, doors, and fascia boards using silicone or acrylic latex caulk. Install door sweeps on all exterior doors and seal gaps under sliding glass doors with foam weatherstripping. Garage doors should have a rubber bottom seal (vinyl performs poorly in cold weather). Plug openings where pipes and wires enter the foundation using caulk, expandable foam, steel wool, or copper mesh.
Repair any torn window and door screens, and install quarter-inch wire mesh over attic, roof, and crawl space vents. These steps block not only seasonal invaders but also flies, gnats, and mosquitoes year-round.
For pantry pests like red flour beetles and Indian meal moths, prevention is about food storage. Transfer dry goods into sealed glass or hard plastic containers, especially flour, cereal, spices, and pet food. Inspect groceries before shelving them, since infestations often start with a product that was already contaminated at the store.
When bugs do get inside, a vacuum cleaner is the most effective and least messy response. This is especially true for Asian lady beetles, since crushing them releases that yellow staining fluid. For larger-scale problems, an exterior barrier treatment with a long-lasting insecticide spray around the foundation, door frames, and utility openings can supplement your sealing efforts. Apply it in late summer or early fall, before the migration indoors begins.