There was a site where people could post map references of sightings but I couldn't find it on a quick search - must look again before summer. Bit spooky going out after dark looking for them though.
Great to have them in your garden! I've seen them, but in a Cambridge chalk-pit nature reserve. It's the females which glow, and they don't fly, so if you've got them, they've probably been around for a while.
Posts
Probably the site someone mentioned
https://www.glowworms.org.uk/