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
Cave Spider
A long-legged orb weaver adapted to the twilight zone of caves, spinning large webs across cavern mouths and dangling its egg sacs from silk threads deep within the darkness.
spider
Fire Ant Queen
The reproductive powerhouse of a fire ant colony, noticeably larger than the reddish worker ants and equipped with wings before she sheds them to found a new nest.
ant
Long-Legged Fly
A jewel-bright little fly that flashes metallic green, blue, or bronze in the sunlight as it darts across leaves on comically long, stilt-like legs, pausing to perform quick territorial displays. Both adults and larvae are active hunters of even smaller insects, making this tiny fly a useful predator in gardens and wetlands alike.
fly
Question Mark Butterfly
A ragged-edged anglewing butterfly named for the tiny silver question-mark squiggle on its mottled brown underside, with tawny-orange upperwings dotted in black.
butterfly
Goliath Birdeater
The heaviest spider in the world, the Goliath birdeater is a massive, hairy tarantula from the South American rainforest whose leg span can rival a dinner plate, though despite its name it primarily hunts insects and other invertebrates rather than birds.
spider
Tachinid Fly
A bristly, house-fly-like insect that looks unremarkable at a glance but hides one of the most important ecological roles among flies: its larvae develop as internal parasites of caterpillars, beetles, and other insects, quietly regulating populations across the landscape. Gardeners often welcome tachinid flies as natural allies against crop-damaging pests.
fly
Fire Ant
A small reddish-brown ant that builds loose, crater-less dirt mounds in sunny open turf and mobilizes large numbers of workers rapidly when the nest is disturbed.
ant
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
Whip Spider
A flattened, spider-like arachnid with no venom and no silk, using a pair of extremely long, whip-like front legs as sensitive feelers to navigate the dark.
arachnid
Flat-backed Millipede
A slow, armor-plated decomposer whose body segments flare into flat, wing-like keels, giving it a distinctly ribbed, tank-like silhouette compared to rounder millipedes.
myriapod
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
Water Stick Insect
An extraordinarily twig-like aquatic predator that lies motionless among pond weed, grasping passing prey with spiny raptorial forelegs while breathing through a long tail-like snorkel.
true-bug
Itch Mite
A microscopic, rounded mite that spends its entire life cycle within the skin of a mammalian host, invisible without a microscope.
arachnid
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
Digger Wasp
A solitary, ground-nesting wasp that excavates neat burrows in bare soil and provisions them with paralyzed prey for its young.
wasp
Punkie
An almost invisibly small biting fly that swarms near wetlands at dusk, where only the females take blood meals from animal hosts.
fly
Stonefly
A flattened, drab-winged insect whose nymphs are among the most reliable living indicators of pristine, well-oxygenated stream water.
aquatic-insect
Alderfly
A small, dusky-winged insect that flutters weakly among streamside alders and shrubs, the diminutive relative of the mighty dobsonfly.
aquatic-insect
Blue-winged Grasshopper
A drab, camouflaged grasshopper that startles onlookers with a sudden flash of bright blue hindwings the instant it takes flight.
grasshopper-cricket
Boxelder Bug (Eastern)
A flat, black true bug boldly trimmed in red-orange lines, famous for massing by the hundreds on sun-warmed walls and tree trunks each autumn.
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
Greenhead Fly
A stout, strikingly green-eyed horse fly that emerges from Atlantic salt marshes in midsummer swarms, where the females bite to feed on blood.
fly
Cluster Fly
A sluggish, dark fly covered in fine golden hairs that gathers by the hundreds on sun-warmed walls in autumn before slipping indoors to spend the winter.
fly