Harmless Bugs You Don't Need to Kill
These bugs look alarming to some people but are harmless. This guide covers 25 of them.
Quick list
- Bold Jumping Spider
- Booklouse
- Camel Cricket
- Cellar Spider
- Common Green Darner
- Common House Spider
- Crane Fly
- Eyed Click Beetle
- Firefly
- Goldenrod Crab Spider
- Green Lacewing
- Ground Beetle
- Harvestman
- House Cricket
- Large Milkweed Bug
- Luna Moth
- Monarch Butterfly
- Mud Dauber
- Periodical Cicada
- Pill Bug
- Praying Mantis
- Seven-Spotted Ladybug
- Spotted Orbweaver
- Springtail
- Yellow Garden Spider
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 25 bugs
Bold Jumping Spider
Bold Jumping SpiderPhidippus audaxA compact, fuzzy black spider with white spots and iridescent green mouthparts. It stalks prey with excellent eyesight and leaps several times its body length.
Tell-tale sign: Two very large, front-facing eyes. Risk: Jumping spiders are shy and harmless; a rare bite feels like a mild pinch.
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.
Camel Cricket
Camel CricketDiestrammena asynamoraA humpbacked, wingless cricket with very long legs and antennae that lives in basements, crawl spaces and garages. It jumps toward threats, which startles many people.
Tell-tale sign: Arched, humpbacked brown body. Risk: Camel crickets don't bite or spread disease; they point to damp conditions.
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 Green Darner
Common Green DarnerAnax juniusA large dragonfly with a bright green thorax and, in males, a blue abdomen. It patrols ponds and fields catching mosquitoes and other flying insects.
Tell-tale sign: Green thorax with a bull's-eye mark on the face. Risk: Dragonflies can't sting and almost never bite people.
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.
Crane Fly
Crane FlyTipula spp.A huge, fragile, long-legged fly often mistaken for a giant mosquito. Adults barely feed, and the larvae, called leatherjackets, eat grass roots.
Tell-tale sign: Extremely long, thin legs that detach easily. Risk: Crane flies cannot bite or sting and do not eat mosquitoes, despite the nickname mosquito hawk.
Eyed Click Beetle
Eyed Click BeetleAlaus oculatusA long, gray-and-black beetle with two large, eye-like spots on its thorax. When flipped over, it snaps a hinge on its body and launches itself into the air with an audible click.
Tell-tale sign: Two large black false eyespots ringed in white. Risk: Eyed click beetles are harmless; the eyespots are a bluff to scare predators.
Firefly
FireflyPhotinus pyralisA soft-bodied beetle that flashes a yellow-green light from its abdomen on summer evenings. Each species uses its own flash pattern to find mates.
Tell-tale sign: Pink or red shield on the thorax with a black center spot. Risk: Fireflies do not bite or sting, but they contain chemicals that are toxic to lizards and some pets if eaten.
Goldenrod Crab Spider
Goldenrod Crab SpiderMisumena vatiaA small, crab-like spider that sits on flowers waiting to ambush bees and flies. It can slowly change color between white and yellow to match its flower.
Tell-tale sign: Front two pairs of legs much longer and held out like a crab's. Risk: Crab spiders are harmless; their fangs are too small to hurt most people.
Green Lacewing
Green LacewingChrysoperla carneaA delicate, pale green insect with golden eyes and clear, net-veined wings. Its larvae, called aphid lions, devour aphids, mites and other soft-bodied pests.
Tell-tale sign: Lacy, transparent wings folded roof-like over the body. Risk: Lacewings are harmless beneficial insects; larvae can occasionally nip skin.
Ground Beetle
Ground BeetleCarabidae familyA fast-running, shiny black beetle that hunts slugs, caterpillars and other insects at night. Ground beetles often wander into basements and garages from nearby mulch and leaf litter.
Tell-tale sign: Shiny black body, often with a metallic sheen. Risk: Ground beetles rarely bite and are beneficial predators; a few release a harmless, bad-smelling spray.
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.
House Cricket
House CricketAcheta domesticusA light yellowish-brown cricket with three dark bands on its head that chirps loudly at night. It wanders indoors in fall and can chew fabric and paper.
Tell-tale sign: Yellowish-brown body with dark crossbands on the head. Risk: House crickets are harmless, though they can damage clothing and keep you awake.
Large Milkweed Bug
Large Milkweed BugOncopeltus fasciatusA bright orange-and-black bug that feeds on milkweed seeds in clusters of adults and nymphs. Its colors warn predators that it tastes bad.
Tell-tale sign: Orange body with a black band across the middle of the back. Risk: Large milkweed bugs are harmless to people and don't damage garden crops.
Luna Moth
Luna MothActias lunaA large, pale lime-green moth with long, sweeping tails on its hind wings. Adults don't eat and live only about a week to mate.
Tell-tale sign: Pale green wings with long, curved hindwing tails. Risk: Luna moths are completely harmless; adults have no functional mouthparts.
Monarch Butterfly
Monarch ButterflyDanaus plexippusAn orange butterfly with black veins and white-spotted borders, famous for its multigenerational migration to Mexico. Its caterpillars feed only on milkweed.
Tell-tale sign: Bright orange wings with thick black veins. Risk: Monarchs are harmless to people but toxic to birds that eat them.
Mud Dauber
Mud DauberSceliphron caementariumA solitary wasp with a thread-thin waist that builds tube-shaped mud nests on walls, ceilings and under porches. It stocks each nest with paralyzed spiders.
Tell-tale sign: Extremely long, thread-like waist. Risk: Mud daubers are non-aggressive and very rarely sting, even when handled.
Periodical Cicada
Periodical CicadaMagicicada septendecimA black cicada with red eyes and orange wing veins that emerges by the millions every 13 or 17 years. Males fill forests with a loud, pulsing chorus.
Tell-tale sign: Black body with bright red eyes. Risk: Cicadas don't bite or sting; egg-laying can damage branch tips on young trees.
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.
Praying Mantis
Praying MantisTenodera sinensisA large, long-bodied predator that waits motionless with its spiny front legs folded as if praying. It catches insects of all kinds, including beneficial ones.
Tell-tale sign: Triangular head that swivels to look over its shoulder. Risk: Mantises are harmless to people, though a large one may pinch if handled.
Seven-Spotted Ladybug
Seven-Spotted LadybugCoccinella septempunctataA rounded, dome-shaped beetle with red wing covers and seven black spots. Both adults and larvae eat aphids, making it one of the most welcome insects in any garden.
Tell-tale sign: Bright red, dome-shaped body. Risk: Seven-spotted ladybugs are harmless to people and pets and do not damage plants.
Spotted Orbweaver
Spotted OrbweaverNeoscona cruciferaA round, hairy orb weaver that builds a new web each evening on porches, eaves and shrubs. By day it hides in a curled leaf or a nearby corner.
Tell-tale sign: Large, round, hairy abdomen, often reddish or orange. Risk: Spotted orbweavers are harmless and help control flying insects.
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.
Yellow Garden Spider
Yellow Garden SpiderArgiope aurantiaA large black-and-yellow orb weaver that spins a big circular web with a thick zigzag band in the center. It sits head-down in the hub of the web in sunny gardens.
Tell-tale sign: Black and bright yellow patterned abdomen. Risk: Yellow garden spiders are not aggressive; a bite is rare and similar to a bee sting.
Which ones should you worry about?
0 of the 25 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 bold jumping spider and booklouse 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.