Cryptozoa is the collective name for small animals who live in darkness and under conditions of high relative humidity, as in the wet soil underneath rocks, decomposing tree bark etc. Examples include pseudoscorpions, slugs, centipedes and earwigs. The habitat of the cryptozoa allows avoidance of fluctuations of temperature and humidity, which makes the contained range of considerably different species quite remarkable. Moreover, cryptozoa are notable for their inclusion of often unnamed varieties of organisms.