A natural history expert says dog walkers can help protect the declining glow-worm population.
Male glow worms are attracted by the female's light
Nick Moyes, assistant keeper at Derby Museum, said the number of glow-worms in chalky grasslands had dropped in the past 15 years.
Dog muck threatens the creatures because it encourages plant growth and makes it hard for the male to find the glowing female to mate.
The insects are found around the UK and live in colonies of less than 100.
Mr Moyes, who monitors glow-worm populations in various areas of Derbyshire, including Coxbench and Mickleover, said the county council had agreed to provide more bins to control the dog-mess problem.
The female glow-worms emit a greenish light, similar to a LED light on a stereo, that is caused when a molecule called luciferin is oxydised.
The glow-worms, which feed on snails by paralysing them before sucking them empty, only mate for a few months in early summer.
Mr Moyes said: "You might see a few dozen on a good night, but in the 1920s there were probably thousands of them around."
They have been identified in the lowland Derbyshire local biodiversity action plan as a species that need protection to ensure their survival.
The three main threats to the glow-worm are changes in habitat, artificial lighting and pesticides.