Please answer the following question: Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Callobius claustrarius - Males of the spider species Callobius claustrarius reach 8 mm females about 11 mm. Head and legs are reddish brown the abdomen is dark grey with an extended brown surface dotted with lighter brown specks.Adults can be found from autumn to spring.This is a palearctic species. In Europe it is found in mountainous regions especially in old moist forests under rocks. C. claustrarius is a rather rare species.The subspecies C. claustrarius balcanicus (Drensky 1940) is only found in Bulgaria.
A:
Animal