It was the strangest request Simon Smith had ever received as operations director of Longwater Gravel Company.

Could he accommodate a visit to the firm's Horstead quarry by a coachload of schoolchildren - bringing along their family of pet aliens.

Youngsters at Horning Primary School created a scary selection of creatures from outer space - in every conceivable shape, size and colour - as the culmination of their project looking at the planets.

And what better place to take them on an outing than a landscape resembling a strange rocky planet?

Mr Smith was keen to host the visit, which included an opportunity for a close-up inspection of the quarry's giant diggers and dumper trucks, as positive PR for an industry which too often suffers from a bad reputation.

He confessed there had been considerable local opposition to Horstead quarry at the planning stage but they had since forged a good reputation with neighbouring residents.

He said: 'There is an understandable fear of the unknown. However, operators these days can't get away with operations that destroy the landscape and everything has to be restored to what it was like before.

'You could easily drive past the site here and not even know what was going on. A good way of reassuring people is to open the gates and let them come and have a look.'

He stressed that sand and gravel were needed for the construction industry - and every tonne excavated in Norfolk was used straightaway.

As the youngsters created a sand fortress for their aliens, and one was buried with just its multiple eyes showing, teacher Dawn Solomka explained the project had stimulated creative writing with pupils composing alien-themed poems.

Her colleague Sally Murphy said: 'In key stage two, we have been looking at impacts on the environment and the pros and cons of having quarries.'

Remarking that the quarry 'looks just like Mars', Ben Ellett, 11, proudly showed off his alien which had five legs and wings.

Hayden Evans, nine, made a den for his alien with just its eyes to be seen.

'He is very shy and some big aliens have been bullying him,' he explained.

During their visit, the youngsters also learned about the geology of the landscape and how it had been formed by a glacier.