Brown long eared bat (credit Tarmac)
The 21 lesser horseshoe bats had been nesting at Rookery Farmhouse, a dilapidated 17th century building on the quarry site.
However Mendip District Council, which owns the building, wanted to restore it after it was given Grade II-listed status.
Working with the council, Natural England and English Heritage, Tarmac commissioned the building of a temporary roost near the farmhouse so that the bats, who have high legal protection in the UK, would have somewhere else to roost while work took place.
Following the completion of restoration work in June 2009, most of the colony has returned to nesting in specially constructed voids in the farmhouse roof.
But one male and three females have remained in the roost, which Tarmac decided to retain.
Henry Andrews, of Bridgwater-based Andrews Ecology, who surveyed the site, said: "It was a long shot and there was a concern that the temporary bat shed wouldn't work, but they took to it straight away."
In addition, following the restoration ten brown long-eared bats have returned to set up a permanent colony in the farmhouse.
Daniel Brailsford, Tarmac's zone manager at Halecombe quarry, said: "We didn't want to rush the project or do anything that would jeopardise the welfare of the bats."
