The 10- and 11-year-old winners of this year’s Rolls-Royce science awards braved health and safety regulations in six months of expeditions to the overgrown rubbish tip behind their school in Bolton.

There, the Year 6 pupils of St Stephen and All Martyrs’ school found and classified earthworms, woodlice, springtails, pseudo-scorpions and other fauna.

Bradford Park tip, which was shut down a few years ago, is a scraggy wilderness covering several square miles.

Robert Moores, a school governor, said the explorations had raised some interesting ethical issues. “A suggestion that we carry out an experiment to see whether the story about chopping a worm in half produces two worms is true stimulated a good discussion, but didn’t pass our quickly-formed pupil ethics committee,” he said.

The 30 children involved in the project have worked with Patricia Francis, a botanist at Bolton Museum, and with the local university and countryside rangers.

One of their expeditions was made at midnight, on the trail of a deer that had been sighted in the area, but the noise of 30 children was enough to alert the deer to make itself scarce.

Michael Cummings, the headteacher, said the school had been looking for ways to fill a practical investigations gap in its science curriculum.

Health and safety regulations often made it difficult to lead trips outside school bounds, so the expeditions had been exciting for the pupils.