Photo of an alderfly larva among rocks and gravel in an aquarium.

    Alderfly Larvae

    Sialis spp.
    Andrenid or miner bee collecting pollen on a flower

    Andrenid Bees (Miner Bees)

    More than 1,200 species in North America north of Mexico
    Acrobat ants on a leaf

    Ants

    More than 700 species in North America
    Longhorn bee visiting a flower, viewed from side

    Apid Bees

    About 1,000 species in North America north of Mexico
    image of Assassin Bug crawling on a leaf

    Assassin Bugs

    Nearly 200 species in North America north of Mexico
    Venomous Icon

    Venomous

    Female spider wasp grasping and dragging body of sac spider
    Banded longhorn beetle on a wild rose

    Banded Longhorn

    Typocerus velutinus
    image of Bee Fly on leaf

    Bee Flies

    About 800 species in North America
    Photo of a meloe blister beetle, female, on ground

    Blister Beetles

    More than 400 species in North America north of Mexico
    Gray, speckled, translucent gelatinous blob cut in half to show structure

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    image of Caddisfly on leaf

    Caddisflies

    About 1,500 species in North America north of Mexico
    Photo of caddisfly larva with case made of detritus

    Caddisfly Larvae

    Various species in the order Trichoptera
    image of a Carolina Grasshopper

    Carolina Grasshopper

    Dissosteira carolina
    Photo of a female scorpionfly perched on a leaf.
    image of a Feather-Legged Fly

    Feather-Legged Flies

    Trichopoda spp.
    image of Firefly crawling on a leaf

    Fireflies (Lightning Bugs)

    Approx. 175 species in North America north of Mexico
    image of a Flower Fly on a flower

    Flower Flies (Syrphids)

    Nearly 900 species in North America
    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    Image of a giant red-headed centipede.

    Giant Red-Headed Centipede

    Scolopendra heros
    Venomous Icon

    Venomous

    Photo of several prosobranch pond snails crawling on a rock.

    Gilled Aquatic Snails (Prosobranch Pond Snails)

    Over 20 Missouri species in former subclass Prosobranchia
    Photo of grass spider poised in funnel of her web

    Grass Spiders

    Agelenopsis spp.
    image of Fiery Searcher on dead leaves

    Ground Beetles

    About 2,400 species in North America north of Mexico
    A metallic green sweat bee gathering pollen on a yellow flowerhead

    Halictid Bees (Sweat Bees)

    More than 500 species in North America north of Mexico
    No photo available

    Hydras

    Various species in the genus Hydra
    image of an Ichneumon Wasp on tree trunk

    Ichneumon Wasps

    More than 5,000 species in North America
    Common true katydid female on a leaf

    Katydids

    About 250 species in North America north of Mexico
    Swamp milkweed leaf beetle on a leaf it has chewed on.

    Leaf Beetles

    About 2,000 species in North America
    image of a Leafhopper on leaf

    Leafhoppers

    More than 3,000 species in North America north of Mexico
    Red milkweed beetle eating a common milkweed leaf.

    Longhorned Beetles (Borers; Sawyer Beetles)

    About 1,000 species in North America north of Mexico
    Photo of pulmonate snail crawling on rock

    Lunged Aquatic Snails (Pulmonate Pond Snails)

    Over 30 Missouri species in former subclass Pulmonata
    Narceus Millipede crawling across gravel

    Millipedes

    More than 900 species in North America north of Mexico
    image of a Mydas Fly

    Mydas Flies

    About 80 species in North America
    Photo of a nursery web spider on a plant

    Nursery Web Spiders

    Pisaurina spp.
    Photo of a robber fly, genus Ommatius, perched on a wall.
    Black and rust-colored wasp on a plant

    Poecilopompilus Spider Wasps

    Poecilopompilus algidus and P. interruptus
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Male eastern Hercules beetle walking in grass

    Scarab Beetles

    About 1,700 species in North America north of Mexico
    Photo of amphipod on a rock

    Scuds and Sideswimmers (Amphipods)

    Species in the crustacean order Amphipoda
    A reddish centipede crawls over a rock

    Soil Centipedes

    Estimated 4,000 species globally
    image of Soldier Beetle on Goldenrod

    Soldier Beetles

    Nearly 500 species in North America north of Mexico
    Glossy black spider wasp manipulating paralyzed spider

    Spider Wasps

    About 300 species in North America north of Mexico
    image of a Stilt-Legged Fly on a leaf

    Stilt-Legged Flies

    About 30 species in North America north of Mexico
    Photo of an aquatic tubificid worm among rocks in an aquarium.

    Tubificid Worms (Tubifex Worms)

    Tubifex spp. and other aquatic tubificid annelids
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    Photo of a collared water scavenger beetle showing back.

    Water Scavenger Beetles

    Beetles in the family Hydrophilidae
    Photo of wolf spider with young

    Wolf Spiders

    Nearly 250 species in North America north of Mexico
    image of Xystodesmid Millipede crawling on a forest floor

    Xystodesmid Millipedes

    8 tribes, with about 23 genera, in North America north of Mexico