The volunteers were trained by the Lost Woods of the Low Weald and Downs project, a partnership that aims to restore some of Sussex’s ancient woodland.
Its senior community development worker, Michael Blencowe, said: “I couldn’t believe they found them, it was remarkable.
“When we started training local groups, I thought the chance of finding any was very, very low.
“Now, we can work with ecologists to protect the dormice at this site and encourage this population’s recovery.”