Q:Aonchotheca forresteri is a parasitic nematode that infects the marsh rice rat (Oryzomys palustris) in Florida. Occurring mainly in adults it inhabits the stomach. It is much more common during the wet season perhaps because its unknown intermediate host is an earthworm that only emerges when it rains. The worm was discovered in 1970 and formally described in 1987. Originally classified in the genus Capillaria it was reclassified in Aonchotheca in 1999. A. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Animal