Queen bat
From Tardis Wiki, the free Doctor Who reference
Queen bats were large, hairy bat-like creatures that lived in the caves of Androzani Minor.
Biology
They had a three year life cycle, some of which was spent in a chrysalis. These chrysalises had a large supply of unrefined spectrox, which was refined and used by the humans of Androzani Major. (TV: The Caves of Androzani)
History
The bats were killed or driven out by the mining androids, which caused them to move into the airless caves deep underground to die. The Fifth Doctor had to climb down the caves to the deep levels, in desperation to obtain Bat milk witch was a cure for him self and Peri who had contracted spectrox poisoning. Sadly the Doctor only managed to milk enough for Peri
