The fact cabinet

Insects

Six legs, three body parts, and most of the minibeasts you’ll ever meet.

• Every adult insect has a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. [source]
• Adult insects are the only arthropods that ever have wings, with up to two pairs on the thorax. [source]
• Insect blood doesn’t carry oxygen, and only some of it stays inside blood vessels. The rest sloshes freely around the body. [source]
• An insect’s hard exoskeleton can’t stretch, so it grows by moulting: shedding its old skin for a bigger one. [source]
• To a scientist, “true bugs” are just one order of insects, the Hemiptera, which includes aphids, cicadas and shield bugs. They all have piercing, sucking mouthparts. [source]
• A beetle’s front wings are hardened into wing-cases called elytra, which cover the delicate flying wings underneath. [source]
• The word “beetle” comes from the Old English bitela, meaning “little biter”. [source]

Seven-spot ladybird · Coccinella septempunctata

• The seven-spot ladybird has three black spots on each wing-case and one more where they meet: seven in all. [source]
• Aphids are the seven-spot ladybird’s main food. [source]
• A ladybird’s bright red-and-black pattern warns predators that it tastes bad. [source]

Stag beetle · Lucanus cervus

• The stag beetle is the largest beetle in Europe. [source]
• A male stag beetle’s huge jaws look like a stag’s antlers and are used in fights with other males, but they’re too weak to hurt you. Females can give a painful nip. [source]
• Stag beetle larvae are blind, C-shaped grubs that feed on rotting wood. [source]

Glow-worm (larva) · Lampyris noctiluca

• Glow-worms aren’t worms at all. They’re beetles, and the wingless females glow to attract males. [source]
• A 2014 study found that even low levels of light pollution can stop male glow-worms finding females. [source]

Common eastern firefly · Photinus pyralis

• Fireflies make “cold light”, with no infrared or ultraviolet in it. [source]
• The common eastern firefly is also called the big dipper firefly, because males flash on the upswing of a J-shaped flight. [source]

Emperor dragonfly · Anax imperator

• The emperor dragonfly is the largest dragonfly in most of Europe, including the UK. Its average wingspan is 104 mm. [source]
• Each of an adult dragonfly’s compound eyes has nearly 24,000 ommatidia, the tiny units that make up an insect eye. [source]
• Dragonflies hunt as underwater nymphs as well as adults, and in some species the nymph stage lasts up to five years. [source]

Peacock butterfly · Aglais io

• A peacock butterfly fends off predators with four big eyespots, and it can also make a hissing sound. [source]
• With its wings closed, a peacock butterfly’s dark underside looks like a dead leaf. [source]

Monarch butterfly · Danaus plexippus

• Monarch butterflies in North America migrate south every autumn, covering thousands of miles to Florida and Mexico. [source]
• Monarch caterpillars grow up on milkweed plants. Females lay their eggs one at a time, usually under a young milkweed leaf. [source]

Red wood ant · Formica rufa

• Red wood ants can spray formic acid from their abdomens to defend themselves. [source]
• Formic acid was first extracted in 1671 by the English naturalist John Ray, who distilled a large number of crushed wood ants. [source]
• You can tell an ant by its elbowed antennae and its slender, knobbly waist. [source]

Leafcutter ant · Atta cephalotes

• Leafcutter ants carry the leaves they cut back to their nests and use them to farm fungus. [source]
• A leafcutter ant can carry up to 50 times its own body weight. [source]

• Griffenflies, giant dragonfly-like insects found in rocks 325 million years old, had wingspans of up to about 750 mm. They were only distant relatives of today’s dragonflies. [source]
• Trap-jaw ants snap their jaws shut faster than any other predatory appendage in the animal kingdom. [source]
• Formic acid was first extracted in 1671 by the English naturalist John Ray, who distilled a large number of crushed wood ants. [source]
• Ladybirds are named after “Our Lady”, Mary, who was often painted wearing a red cloak. [source]

Spiders and other arachnids

Eight legs, no antennae, and silk.

• Spiders belong to the arachnids, along with scorpions, ticks, mites and harvestmen. [source]

European garden spider · Araneus diadematus

• Spiders have eight legs, fangs that can usually inject venom, and spinnerets that make silk. [source]
• Weight for weight, spider silk is stronger than steel, and it’s tougher than both steel and Kevlar. [source]
• Spiders have no muscles to straighten their legs. They push them out with fluid pressure instead. [source]

Zebra spider · Salticus scenicus

• The zebra spider is a jumping spider with eight eyes, and the two at the front are especially big. [source]
• Most spiders live for two years at most, but tarantulas can live for more than 20. [source]

Centipedes and millipedes

Lots of legs, but never quite as many as the names suggest.

Brown centipede · Lithobius forficatus

• No centipede has exactly 100 legs. They always have an odd number of pairs, from 15 to 191. [source]
• A centipede’s “fangs” are really its front pair of legs, changed into venomous pincers called forcipules. [source]
• Centipedes have one pair of legs on each body segment. [source]

Pill millipede · Glomeris marginata

• The pill millipede rolls into a ball when disturbed, so it often gets mistaken for a pill woodlouse. [source]
• Millipedes have two pairs of legs on most body segments. [source]
• “Millipede” means “thousand feet”, but no millipede was known to have 1,000 legs until Eumillipes persephone was discovered in 2020, with over 1,300. [source]

Woodlice

The crustaceans that moved onto land.

• Isopods are an order of crustaceans. [source]

Common woodlouse · Oniscus asellus

• Woodlice are isopods, and isopods are crustaceans, so a woodlouse is a crustacean that lives on land, not an insect. [source]
• A woodlouse has seven pairs of legs, which makes 14 legs in total. [source]
• Woodlice eat their own droppings to get more goodness out of tough leaf litter. [source]

• Female woodlice carry their eggs in a pouch called a marsupium. [source]
• Woodlice are crustaceans, and they’ve been described as tasting similar to other crustaceans. [source]

Snails and slugs

Gastropods: molluscs that glide on one muscular foot.

• Snails and slugs are both gastropods, a group of molluscs. [source]

Roman snail · Helix pomatia

• When it hibernates, the Roman snail can seal its shell with a chalky door called an epiphragm. [source]
• The Roman snail’s maximum lifespan is 35 years. [source]
• In England the Roman snail is protected under the Wildlife and Countryside Act 1981, so it’s illegal to kill, injure, collect or sell one. [source]

Leopard slug · Limax maximus

• Leopard slugs mate hanging in mid-air from a thick rope of slime. [source]
• Slugs evolved from shelled ancestors many separate times, so the different slug families aren’t closely related. [source]

Black slug · Arion ater

• Despite its name, the black slug isn’t always black. Some adults are brown or even white. [source]
• Most snails have a ribbon-like tongue called a radula, covered in thousands of microscopic tooth-like structures. It works like a file, rasping food into small pieces. [source]

Earthworms

Segmented worms, and very good for soil.

• Earthworms are annelids, or segmented worms, the same group as ragworms and leeches. [source]

Common earthworm · Lumbricus terrestris

• Earthworms breathe through their skin, so it has to stay moist. [source]
• Most earthworms are both male and female at once. When two mate, each fertilises the other’s eggs. [source]
• Earthworms have no single heart. Paired blood vessels called aortic arches, in segments seven to eleven, do the pumping. [source]

• In 1881 Charles Darwin wrote that few animals had “played so important a part in the history of the world” as earthworms. [source]
• In Britain the common earthworm is also called the lob worm. In North America it’s the nightcrawler. [source]

Water bears

Tiny, tough and found almost everywhere.

• Tardigrades, or water bears, are eight-legged micro-animals, usually about 0.5 mm long when fully grown. [source]
• Tardigrades have survived exposure to outer space. [source]
• Tardigrades were first described in 1773, by the German zoologist Johann August Ephraim Goeze. [source]