Relics: The pink slug, above, eats mould and moss.
High in the mists that shroud Mount Kaputar, near Narrabri in north-western NSW, scientists have discovered a secret world.
By day it is an isolated pocket of snow gums, wrapped in straggling native vines.
People tend to focus on the cute and cuddly bird and mammal species like koalas. But these little invertebrates drive whole ecosystems.
But on rainy nights, it is the domain of giant, fluorescent pink slugs - up to 20 centimetres long - and carnivorous, cannibal land snails that roam the mountaintop in search of their vegetarian victims.
''It's just one of those magical places, especially when you are up there on a cool, misty morning,'' said Michael Murphy, a national parks ranger for 20 years, whose beat covers the mountain top.