Insects & Invertebrates
Insects are the most species-rich class of animals on Earth — with over one million described species and estimates of the true total running far higher. Together with other invertebrates such as spiders, they have colonised virtually every land and freshwater habitat and perform ecological functions indispensable to global food systems, including pollination, decomposition, and forming the base of many food webs.
Insect & Invertebrate Profiles
Each profile is a cautious, group-level overview rather than a single-species monograph. We cover anatomy, life cycle, habitat, diet, and ecological role, and we note where a common name spans many species. Spiders are included here as familiar invertebrates, with a clear reminder that they are arachnids, not insects.
Bee
Clade Anthophila — vital pollinators; a group-level overview using the honey bee.
Butterfly
Order Lepidoptera — day-flying insects with a four-stage life cycle.
Ant
Family Formicidae — highly social insects living in organised colonies.
Dragonfly
Infraorder Anisoptera — fast aerial predators with aquatic larvae.
Ladybug
Family Coccinellidae — small beetles, many of them helpful aphid predators.
Praying Mantis
Order Mantodea — ambush predators with grasping forelegs and keen eyesight.
Spider
Order Araneae — eight-legged arachnids (not insects) that produce silk.
Beetle
Order Coleoptera — the most species-rich animal group, with hardened wing cases.
Scorpion
Order Scorpiones — arachnids with pincers and a venomous tail sting.
Earthworm
Annelida — segmented worms that aerate and enrich the soil.
Tarantula
Theraphosidae — large, hairy spiders, mostly calm and only mildly venomous.
Centipede
Chilopoda — fast, venomous, many-legged predators (one leg pair per segment).
Millipede
Diplopoda — slow, harmless litter recyclers (two leg pairs per segment).
Moth
Lepidoptera — mostly night-flying insects that outnumber butterflies.
Grasshopper
Caelifera — plant-eating insects with powerful jumping legs.
Snail
Shelled gastropod molluscs that glide on a muscular foot.
Slug
Shell-less gastropod molluscs; close relatives of snails.
Cicada
Family Cicadidae — loud summer singers whose nymphs live underground for years.
Cricket
Family Gryllidae — chirping insects that sing by rubbing their wings.
Stick Insect
Order Phasmatodea — masters of camouflage that mimic twigs and leaves.
Wasp
Order Hymenoptera — feared for their sting, but vital pest controllers and pollinators.
Termite
Order Isoptera — social wood-recyclers and mound-builders (actually a kind of cockroach).
Tardigrade (Water Bear)
Phylum Tardigrada — microscopic animals that survive almost anything, even space.
Cockroach
Order Blattodea — ancient, hardy insects; mostly wild recyclers, a few are pests.
Crayfish
Lobster-like freshwater crustaceans; recyclers, and invasive where introduced.
Velvet Worm
Phylum Onychophora — ancient soft-bodied predators that shoot sticky slime.
Mayfly
Order Ephemeroptera — short-lived adults; nymphs indicate clean fresh water.
Woodlouse
Suborder Oniscidea — the only crustaceans fully adapted to land; harmless soil recyclers.
Lacewing
Order Neuroptera — lacy-winged insects whose 'aphid lion' larvae devour garden pests.
Aphid
Family Aphididae — tiny sap-suckers that clone themselves and are 'farmed' by ants for honeydew.
Antlion
Family Myrmeleontidae — larvae ('doodlebugs') dig conical sand traps to catch ants.
Weevil
Family Curculionidae — long-snouted beetles; one of the largest animal families, with notable crop pests.
Thrips
Order Thysanoptera — minuscule fringe-winged insects; pollinators and pests ('thrips' is singular too).
Earwig
Order Dermaptera — pincer-tailed insects that guard their young; the ear-burrowing tale is a myth.
Leafhopper
Family Cicadellidae — small sap-sucking jumpers that coat themselves in water-repelling brochosomes; many are crop pests.
Why Insects & Invertebrates Matter
Insects pollinate a large share of the world's flowering plants and many food crops, while beetles, flies, and other invertebrates are primary decomposers that break down organic matter and cycle nutrients back into soil. Spiders and predatory insects help regulate the numbers of other invertebrates. Many vertebrate species — including birds, fish, amphibians, and mammals — depend on insects and other invertebrates as a primary food source. Documented declines in some insect populations are a significant ecological concern with cascading effects across ecosystems.