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
Bark Louse
A small, soft-bodied insect often seen in dense, moving herds on tree trunks, the bark louse grazes on algae, lichen, and fungal residue coating bark surfaces.
other
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
Stonefly Nymph
A flattened, armored aquatic nymph that clings tightly to rocks in swift, cold streams, serving as one of the most reliable signs of pristine water quality.
aquatic-insect
Damselfly Nymph
A slender aquatic predator with three feathery tail gills, patiently stalking small prey among pond plants before emerging as a delicate flying damselfly.
aquatic-insect
Dragonfly Nymph
A stocky, camouflaged underwater predator that spends months or years stalking prey along the pond bottom before transforming into an aerial dragonfly.
aquatic-insect
Common Wood-Nymph
A large brown grassland butterfly with a bold yellow patch and one or two prominent black eyespots on the forewing, known for its bouncing, low-to-the-ground flight.
butterfly
Death's-head Hawkmoth
A large, thick-bodied hawkmoth instantly recognized by the pale, skull-and-crossbones marking on its furry thorax, famous for entering beehives and letting out a shrill squeak when disturbed.
moth
Broad-Headed Bug
A slender, dark true bug with a notably wide head, whose nymphs are remarkable ant mimics that scurry among leaf litter before maturing into fliers that resemble small leaf-footed bugs.
true-bug
Cone-headed Katydid
A large, grass-colored katydid named for its sharply pointed, cone-shaped head, best known for producing some of the loudest, most sustained buzzing calls of any North American insect.
grasshopper-cricket
Lantern Bug (Peanut-head Bug)
A bizarre rainforest planthopper whose head is drawn out into a huge, hollow, peanut-shaped snout, and whose hindwings flash a pair of large eyespots resembling the face of a small reptile.
true-bug
Psyllid
A tiny, sap-sucking hopper that resembles a miniature cicada and springs away in a blur when its host leaf is disturbed.
true-bug
Aphid
A tiny, soft-bodied, pear-shaped insect that clusters in dense colonies on plant stems and leaf undersides, feeding on sap through needle-like mouthparts and often coated in sweet honeydew.
true-bug
Fishfly Larva
A flattened, armor-plated predator of stream bottoms, the fishfly larva spends one to three years underwater seizing prey with sickle-shaped jaws before briefly taking wing as a short-lived winged adult.
aquatic-insect
Mouse Spider
A stout, glossy burrowing spider named for its supposed mouse-like agility, with males often sporting a strikingly colored head and jaws.
spider
Ant-mimicking Mantis
As a tiny nymph, this mantis moves in quick, jerky bursts to imitate a scurrying ant, a clever disguise it gradually sheds as it grows into a typical-looking adult mantis.
mantis-stick
Meadow Spittlebug
A small, mottled hopping true bug whose immature nymphs are far more often noticed than the adults, hidden inside frothy blobs of white foam known as cuckoo spit on plant stems.
true-bug
Stonefly
A flattened, drab-winged insect whose nymphs are among the most reliable living indicators of pristine, well-oxygenated stream water.
aquatic-insect
Spittlebug
A small hopping true bug best known in its nymph stage, which surrounds itself in a frothy mass of white foam on plant stems, commonly called cuckoo spit.
true-bug
Question Mark Caterpillar
A spiny, variably colored caterpillar named for the silver question-mark-shaped mark on the underside of the adult butterfly's wings.
caterpillar-larva
Bordered Plant Bug
A dark, oval-bodied true bug with a distinct pale margin around its wing edges, often mistaken for a large ant or beetle when its nymphs cluster together in tight groups.
true-bug
Mosquito Larva
A wriggling, comma-shaped aquatic larva that hangs from the water's surface to breathe before transforming into a flying adult mosquito.
aquatic-insect
Black Soldier Fly
A sleek, dark, wasp-like fly whose larvae are voracious decomposers of decaying organic material, while the short-lived adults do not feed at all.
fly
Mourning Cloak Butterfly
A deep maroon-brown butterfly bordered with a cream-yellow band and a row of iridescent blue spots, unusual among butterflies for overwintering as an adult and being one of the first to appear in early spring.
butterfly