Sometimes different feeding habits involve morphologically distinct phases, but they may involve only behavioral differences, and sometimes depend only on the immediate availability of different foods. Some life cycles involve a definite progression of particular hosts and depend on the life cycle of the host. Fungal feeders may have life cycles as short as 5 days.
Some are associated with insects, and may be ectoparasites or endoparasites, or merely use the insect as transport. Others are associated with plants, as root, stem, or leaf parasites, which may be pathogenic to the plant or not. Still others are associated with fungi, and some are free-living.