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Glow Worms

To find out more about Glow worms you can watch this short wildlife documentary by Chris Gent. It covers the life cycle of one of Britain's most adored yet mysterious insects, and explores the modern day threats and challenges posed to their future existence.

The male glow-worm looks like an ordinary beetle with hard wing cases, however the flightless female has flattened body sections and no wings at all.

male glow worm
Male glow worm (Phosphaenus hemipterus) © John Horne

The female is larger than the male and she can produce a bright greenish-yellow glow from the underside of the last two sections of her body. This glow is caused by a chemical reaction within the beetle and it is used to attract a mate. It’s not unusual to find several male glow-worms trying to mate with the same female! The females glow for several hours at a time as soon as it gets dark but switch off their glow once they have mated.

female glow worm
Female glow worm © John Horne

Young glow-worms look very like the wingless females, however they produce a weak intermittent light that is easily overlooked.

Click here to find out more about these amazing creatures on the UK glow worm survey home page.