Tiny Bugs: Identify Small Specks That Move
Tiny bugs under 5 mm are hard to identify. Here's how to tell them apart. This guide covers 20 of them.
Quick list
How to narrow it down
Narrow it down with three quick checks. Count the legs: insects have six, spiders and ticks have eight, and centipedes and millipedes have many more. Check for wings, even folded ones. Then compare size against a coin: a US penny is 19 mm across. Our bug identifier tool does this filtering for you.
The 20 bugs
Cat Flea
Cat FleaCtenocephalides felisThe most common flea on both cats and dogs, a tiny, flattened, dark insect that jumps huge distances. Eggs drop off pets into carpets and bedding.
Tell-tale sign: Tiny, reddish-brown to black body flattened side to side. Risk: Flea bites itch, can cause allergic dermatitis in pets, and fleas can pass tapeworms.
Chigger
ChiggerTrombiculidae familyThe nearly invisible red larva of a harvest mite that attaches to skin in grassy, brushy areas. Chiggers feed on skin cells, not blood, and cause intensely itchy red bumps.
Tell-tale sign: Microscopic red or orange specks, barely visible. Risk: Chigger bites itch for days, but in the US chiggers don't transmit disease.
Head Louse
Head LousePediculus humanus capitisA tiny, wingless insect that lives only on the human scalp and feeds on blood. Its eggs, called nits, are glued firmly to hair near the scalp.
Tell-tale sign: Sesame-seed-size tan or grayish insect on hair. Risk: Head lice are itchy but don't spread disease; they spread mainly by head-to-head contact.
Aphid
AphidAphidoidea superfamilyA tiny, soft, pear-shaped insect that clusters on new shoots and leaf undersides to suck sap. Aphids reproduce quickly and leave sticky honeydew that attracts ants.
Tell-tale sign: Pear-shaped, soft body, often green or black. Risk: Aphids don't bite people; heavy colonies curl leaves and spread plant viruses.
Argentine Ant
Argentine AntLinepithema humileA small, light-to-dark brown ant that forms huge, cooperating supercolonies. Wide, busy trails often stream into kitchens during hot or rainy weather.
Tell-tale sign: Uniform light-brown body with one flat node. Risk: Argentine ants don't sting and rarely bite; they protect aphids and scale insects on garden plants.
Cigarette Beetle
Cigarette BeetleLasioderma serricorneA tiny, humpbacked, reddish-brown beetle that infests tobacco, spices, dried flowers, cereals and pet food. Adults are strong fliers and are often found near windows.
Tell-tale sign: Rounded, humped body with smooth, ungrooved wing covers. Risk: Cigarette beetles do not bite; they contaminate and damage stored products.
Clover Mite
Clover MiteBryobia praetiosaA tiny, red-brown mite that crawls by the thousands onto sunny walls and windowsills in spring and fall. Crushed mites leave red stains.
Tell-tale sign: Pinhead-size red to brown dots moving on walls. Risk: Clover mites don't bite people or damage homes; they're a staining nuisance.
Confused Flour Beetle
Confused Flour BeetleTribolium confusumA flat, slender, reddish-brown beetle common in flour, cake mixes, cereals and other milled foods. Heavy infestations leave a grayish tint and a sharp, unpleasant smell.
Tell-tale sign: Flat, elongated reddish-brown body. Risk: They don't bite or sting; infested flour tastes and smells bad.
Drugstore Beetle
Drugstore BeetleStegobium paniceumA small, reddish-brown pantry beetle with rows of fine grooves along its wing covers. It infests dried foods, spices, pet food, and even books and medicines.
Tell-tale sign: Oval, reddish-brown body with lengthwise grooves. Risk: Drugstore beetles don't bite or spread disease, but they ruin stored food.
Fruit Fly
Fruit FlyDrosophila melanogasterA tiny, tan fly with bright red eyes that hovers over ripe fruit, drains, trash and spilled drinks. It can go from egg to adult in about a week.
Tell-tale sign: Very small tan body with bright red eyes. Risk: Fruit flies don't bite; they can carry bacteria from trash onto food.
Fungus Gnat
Fungus GnatBradysia spp.A tiny, dark, mosquito-like fly that hovers around houseplants and windows. Its larvae live in moist potting soil and feed on fungi and roots.
Tell-tale sign: Delicate dark body with long legs and antennae. Risk: Fungus gnats don't bite; larvae can damage seedlings and young roots.
Little Black Ant
Little Black AntMonomorium minimumA tiny, jet-black, shiny ant that nests in lawns, under rocks and in wall voids. Workers form narrow trails to sweets, grease and meats.
Tell-tale sign: Very small, glossy jet-black body. Risk: Little black ants have a sting too weak to feel; they are a nuisance only.
Longhorn Crazy Ant
Longhorn Crazy AntParatrechina longicornisA dark, slender ant with extremely long legs and antennae that runs in fast, jerky, seemingly random paths. It nests in soil, trash and wall voids, mostly in warm southern states.
Tell-tale sign: Long legs and antennae relative to its body. Risk: Crazy ants rarely bite and don't sting; their sheer numbers make them a nuisance.
Odorous House Ant
Odorous House AntTapinoma sessileA small, dark brown to black ant that trails along counters and sinks looking for sweets. Crushed workers give off a smell often compared to rotten coconut.
Tell-tale sign: Small, uniformly dark ant with an uneven thorax. Risk: Odorous house ants are a nuisance only; they rarely bite and don't sting.
Pavement Ant
Pavement AntTetramorium immigransA dark brown ant that nests under sidewalks, driveways and slabs, pushing up small piles of sand. Colonies fight noisy battles on pavement in spring.
Tell-tale sign: Parallel grooves on the head and thorax. Risk: Pavement ants have a weak sting that rarely bothers people; they are mainly a nuisance.
Pharaoh Ant
Pharaoh AntMonomorium pharaonisA tiny, pale yellow ant that nests in warm, hidden spots inside walls, cabinets and appliances. Colonies split into new nests when disturbed, which makes them hard to control.
Tell-tale sign: Very small, light yellow to amber body with a darker abdomen. Risk: They don't bite, but in hospitals and kitchens they can carry bacteria onto clean surfaces.
Rice Weevil
Rice WeevilSitophilus oryzaeA small, dark weevil with a long snout and four faint reddish spots on its back. Females chew holes in whole grains such as rice, wheat and corn and lay an egg inside each kernel.
Tell-tale sign: Long, narrow snout extending from the head. Risk: Rice weevils cannot bite people and are not harmful if accidentally eaten, but they spoil grain.
Varied Carpet Beetle
Varied Carpet BeetleAnthrenus verbasciA tiny, round beetle mottled with white, brown and yellow scales. The fuzzy, banded larvae chew holes in wool, silk, feathers, leather and stored animal products.
Tell-tale sign: Very small, round beetle with a mottled scale pattern. Risk: Carpet beetles don't bite, but larval hairs can cause itchy skin rashes in some people.
Booklouse
BooklouseLiposcelis spp.A tiny, soft, pale insect that feeds on microscopic mold growing on paper, cardboard and stored food. It thrives in humid rooms and new construction.
Tell-tale sign: Very small, pale, wingless body. Risk: Booklice don't bite and aren't true lice; they indicate high humidity and mold.
Springtail
SpringtailCollembola classA tiny, wingless hexapod that jumps using a tail-like spring folded under its body. Springtails swarm in damp soil, potted plants and around leaks.
Tell-tale sign: Pinhead-size gray, white or black body. Risk: Springtails don't bite or damage homes; large numbers usually point to a moisture problem.
Which ones should you worry about?
3 of the 20 bugs in this guide can bite or sting. None of them are considered medically significant. The rest are harmless or simply a nuisance.
Frequently asked questions
What is the most common one?
Among the bugs in this guide, the cat flea and chigger are the ones people ask about most.
Which of these are dangerous?
None of them are medically significant, though some can bite or sting.
How can I identify a bug I found?
Use the free bug identifier tool: choose the number of legs, wings, main color, size and where you found it, and it will list the closest matches.