Bug Encyclopedia
Search and identify bugs & insects — beetles, butterflies, moths, ants, bees, spiders and more — with size, habitat, danger, behavior, and how to tell them apart.

Louse Fly
A flattened, leathery-bodied fly that clamps onto fur or feathers with stout claws and scuttles sideways like a tiny crab rather than taking flight when disturbed. Several species shed their wings for good once they settle on a permanent host, spending the rest of their lives buried in fleece or plumage.
fly
Pseudoscorpion
A tiny, tail-less relative of true scorpions, complete with a pair of oversized pincers on a body barely bigger than a grain of rice. Often overlooked entirely, it spends its life hunting even smaller arthropods in leaf litter, bark, and sometimes old books.
arachnid
Marsh Treader
An extremely slender, thread-like true bug that walks slowly and deliberately across the water's surface on stilt-like legs, resembling a tiny floating twig as it hunts among marsh vegetation.
aquatic-insect
Hag Moth Caterpillar (Monkey Slug)
One of the strangest caterpillars in North America, with curling, hair-covered arm-like projections that make it look uncannily like a tiny tuft of matted fur or a miniature spider monkey.
caterpillar-larva
Tailless Whip Scorpion
A flattened, spider-like arachnid with no stinger and no fangs, instead using a pair of long whip-like sensory legs and grasping spiny arms to feel out and seize prey in total darkness.
arachnid
Puss Moth
A stout, furry gray-and-white moth named for its dense, cat-like coat of hair, best known for its bizarre green caterpillar with a hump-backed, face-like front end and forked tail filaments used in defensive displays.
moth
Water Mite
A brilliantly colored, ball-shaped mite that swims through freshwater ponds and streams using fringed, oar-like legs.
arachnid
Itch Mite
A microscopic, rounded mite that spends its entire life cycle within the skin of a mammalian host, invisible without a microscope.
arachnid
Peck's Skipper
A tiny, tawny-orange and brown skipper with a bold, irregular yellow patch on the underside of the hindwing that looks almost like a splash of paint.
butterfly
Sod Webworm
A dull, grayish-green caterpillar that hides in silk-lined burrows by day and emerges at night to chew grass blades down to the thatch.
caterpillar-larva
Buck Moth Caterpillar
A dark, spiny caterpillar covered in branched spines that marches across oak-lined sidewalks in dense groups each spring.
caterpillar-larva
Blow Fly
A brilliant, metallic green fly that gleams like a jewel in sunlight, quickly locating decaying material with an acute sense of smell.
fly
Bird-dropping Spider
A lumpy, white-and-brown orb-weaver that spends its days motionless on a leaf, looking uncannily like a fresh splash of bird droppings.
spider
Robber Fly
A powerfully built, bristly-faced predatory fly that ambushes other flying insects in midair, piercing them with a stout beak-like proboscis.
fly
Comet Moth (Madagascan Moon Moth)
One of the largest and most spectacular silk moths in the world, with pale yellow-to-red wings and extraordinarily long, ribbon-like tails on the hindwings.
moth
Tube Web Spider
A sleek, cylindrical spider that lives inside a silk-lined tube and dashes out to seize insects that stumble across its radiating trip-lines.
spider
Io Moth Caterpillar
A bright lime-green caterpillar bristling with clusters of branching, stinging spines and thin red and white racing stripes along its sides.
caterpillar-larva
Stinging Rose Caterpillar
A boldly striped slug caterpillar in candy-like tones of yellow, orange, and purple, crowned with tufted spine clusters that can sting on contact.
caterpillar-larva
Snakefly
A slender predator named for its habit of rearing up its long, mobile neck like a tiny cobra when hunting or threatened.
other
Midge
A slender, mosquito-like fly that forms dense swarms near water at dusk, easily mistaken for a mosquito but lacking any biting mouthparts.
fly
Walking Stick Insect
A master of disguise that has evolved to look almost exactly like a twig, bark or leaf, remaining motionless for hours to avoid the notice of hungry birds and lizards.
mantis-stick
Water Boatman Bug
A boat-shaped little swimmer that rows through pond water with oar-like hind legs, grazing on algae rather than hunting other animals.
true-bug
Mayfly Nymph
A short-lived aquatic grazer with feathery gills along its abdomen, living for months underwater before a brief, spectacular mass emergence as a winged adult.
aquatic-insect
Northern Walkingstick
A slender, wingless insect so convincingly shaped like a twig that it can rest motionless on a branch just inches from view and go completely unnoticed.
mantis-stick