Quick facts

Common name(s): glow-warm

Scientific name: Lampyris noctiluca

Family: Lampyridae

Habitat: grassland, hedgerows and woodland edges

Diet: nothing as adults, slugs and snails as larvae

Predator: birds

Origin: native

What do glow-worms look like?

Adults: can grow up to 25mm long. Females are larger than males and both have segmented bodies. The females have bioluminescence that produce the glow but males only emit a small amount of light. Males also have wings where females do not.

Larvae: are similar looking to females but have light spots on either side of each body segment.

What do glow-worms look like?

Adults: can grow up to 25mm long. Females are larger than males and both have segmented bodies. The females have bioluminescence that produce the glow but males only emit a small amount of light. Males also have wings where females do not.

Larvae: are similar looking to females but have light spots on either side of each body segment.

What do glow-worms eat?

Glow worms do all their eating as larvae. They feed on slugs and snails by injecting their digestive juices into their prey and drinking the digested remains. Adults don't even have mouthparts.

Glow-worm larva resting on a leaf

Credit: FLPA / Alamy Stock Photo

How do glow-worms breed?

Females use their bioluminescence to attract mates. Adults only live for a few weeks to breed and die soon after. Females can lay up to 100 eggs which are laid on the ground. The hatched larvae feed and grow for about two years before fully maturing.

Did you know?

Adults burrow under the soil during the day to avoid predators, then emerge at night to put on a light show.

Where do glow-worms live?

You can find glow worms in parts of Britain in grassland and woodland edges. They are not present in Northern Ireland.

Signs and spotting tips

You can spot glow-worms between June and July in grass and shrub far away from artificial lights. Look out for a bright light after it has become completely dark outside.

Threats and conservation

Whilst glow-worms remain fairly common, there is some concern about possible declines, and they have vanished from some sites. Possible threats include changes in land-use and habitat, use of pesticides, light pollution, and possibly parasites.

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