Gray Bugs Without Wings: 13 Types
These are the 13 most common gray bugs without wings found in North America.
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 13 bugs
American Dog Tick
American Dog TickDermacentor variabilisA brown tick with ornate white-gray markings on its shield, common along trails, roadsides and grassy fields. It readily feeds on dogs and people.
Tell-tale sign: Brown body with silvery-white mottling on the shield. Risk: American dog ticks can transmit Rocky Mountain spotted fever and tularemia.
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.
Wolf Spider
Wolf SpiderLycosidae familyA large, hairy, fast-running spider that hunts on the ground instead of building webs. Females carry their egg sacs and then their spiderlings on their backs.
Tell-tale sign: Hairy brown or gray body with dark stripes. Risk: Wolf spiders can bite if handled, causing pain and swelling like a bee sting, but they're not dangerous.
House Centipede
House CentipedeScutigera coleoptrataA fast, yellowish-gray centipede with 15 pairs of very long legs that races across floors and walls at night. It hunts silverfish, cockroaches and spiders.
Tell-tale sign: Fifteen pairs of long, banded legs. Risk: House centipedes rarely bite; a bite feels like a mild bee sting.
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.
Silverfish
SilverfishLepisma saccharinaA wingless, carrot-shaped insect covered in silvery scales that moves with a fish-like wiggle. It eats paper, glue, starches and fabrics in damp areas.
Tell-tale sign: Silvery-gray, teardrop-shaped, scaly body. Risk: Silverfish don't bite; they damage books, wallpaper and stored papers.
Southern House Spider
Southern House SpiderKukulcania hibernalisA velvety, dark gray to brown spider of the southern US whose males look like brown recluses. Females build radiating, lint-like webs around cracks in walls and windows.
Tell-tale sign: Velvety, uniformly dark females with a small head. Risk: Southern house spiders rarely bite and are not medically significant.
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.
Cellar Spider
Cellar SpiderPholcus phalangioidesA pale, delicate spider with extremely long, thin legs that hangs upside down in loose webs in basements and ceiling corners. When disturbed, it vibrates rapidly in its web.
Tell-tale sign: Tiny, peanut-shaped body with very long, hair-thin legs. Risk: Cellar spiders are harmless to people; the myth that they are deadly but can't bite is false.
Common House Spider
Common House SpiderParasteatoda tepidariorumA small, brownish spider that builds tangled cobwebs in corners, windows and basements. It is the web-builder most often seen inside North American homes.
Tell-tale sign: Round, mottled brown abdomen with chevron markings. Risk: Common house spiders are harmless and help catch flies and other indoor pests.
Harvestman
HarvestmanOpiliones orderOften called daddy longlegs, a long-legged arachnid with a single fused, oval body and no venom glands. It scavenges on dead insects, fungi and plant matter.
Tell-tale sign: One round body section instead of two. Risk: Harvestmen have no venom and no silk; they are completely harmless.
Pill Bug
Pill BugArmadillidium vulgareA small land crustacean that rolls into a tight ball when disturbed, also called a roly-poly. It eats decaying plant matter in damp soil and mulch.
Tell-tale sign: Gray, armored, segmented body with seven pairs of legs. Risk: Pill bugs are harmless and only occasionally nibble seedlings.
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 13 bugs in this guide can bite or sting. The ones to take seriously are American dog tick. The rest are harmless or simply a nuisance.
Frequently asked questions
What is the most common one?
Among the bugs in this guide, the American dog tick and head louse are the ones people ask about most.
Which of these are dangerous?
American Dog Tick can be medically significant.
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.