Posted 19th Jun 2017
The glow-worm is not actually a worm at all, but is instead a small beetle, typically found in meadows, grassland and hedgerows
Glow-worms will live for up to three years as predatory larvae, living under rocks and hidden deep in grassy tussocks where they will feed on snails. Once they've matured, they will emerge as adults, who are active for just a few weeks of the summer.
It is the flightless female which does most of the glowing, climbing up into tall grasses on still, dark evenings. It is then that they will produce the greenish light, as a way of attracting passing males as they fly along the open areas beside hedgerows, paths and embankments, in search of a mate. The bioluminescence is created by a chemical reaction that occurs in the beetle's abdomen. It's not only the female that will glow - larvae can do it as well, and even the eggs can emit light.
When to see them
Late June and early July is the ideal time to go on a glow-worm hunt. Choosing a still, warm evening with a crescent moon is the ideal time - glow worms are less likely to glow when there is a full moon. You should also avoid a torch and instead, let your eyes adjust to the dark. You are then more likely to be able to pick out the faint green illumination of the glow-worm.
Glow-worms are dotted across most of England and Wales, but are a relatively rare sight in Scotland. They're at their most numerous on calcareous grasslands, where there are plenty of small snail species for them to feed on.
An area worth visiting could be your local grassland nature reserve after dark, so you can see what you find.
Glow-worms gleam at Bystock Pools near Exmouth, Devon. During some summer nights the number of lights can approach 100 in the reserves grassland, a magical sight on a late evening walk.
Cambridgeshire, Cherry Hinton Chalk Pits
Essex, Iron Latch - join a glow-worm walk in summer
Suffolk, Blaxhall Common
Suffolk, Newbourne Springs
Image courtesy of © John Tyler
Information courtesy of The Wildlife Trusts