While nematodes may incidentally ingestnon-living material,
it is generally accepted that they require living organisms
in their diet. Soil-dwelling nematodes can be
functionally separated into five broad trophic groups
(Wasilewska 1971): (1)microbivores; (2) fungivores; (3)
plant parasites; (4) predators; and (5) omnivores. These
categories are not mutually exclusive; some species always
placed in one category may in fact have developmental
stages or generations that fit another category.