Up to 10% of the total British population of Greater Horseshoe Bat use the quarries at times, and a maximum of 230 individuals of the species have been counted. The Lesser Horseshoe Bat also uses the quarries, as do the four Myotis species: Whiskered, Brandt’s, Natterer’s and Daubenton’s bats.
Bats are a protected species in the UK and consequently conservation is a major concern with regard to the disused quarries. Obviously they require access to the underground chambers so grilles must be fitted rather than doors to allow them to pass through. In the winter months they may be found hibernating on the walls of the quarries but they must not be disturbed under any circumstances.
Millipedes have been found eating decaying wood underground.
In 1927 Lowndes discovered Bathynella chappuisi a subterranean freshwater syncarid crustacean in Pickwick Quarry