Consumers are sometimes synonymously known as heterotrophs ("other feeders"), although it is best to exclude decomposers from this group. Consumers include a diverse group of organisms that depend on plants and animals for their nutrition. Although most plants are autotrophs (primary producers), the insectivorous plants and a few protistan algae are heterotrophic. Consumers cannot synthesize their own organic matter, and are grouped within the food chain as primary consumers (herbivores), secondary consumers (primary carnivores), tertiary consumers (secondary carnivores), and so on. An example of this type of food chain in the terrestrial environment might include rabbits, weasels, foxes, and coyotes. A similar example in an aquatic ecosystem might include zooplankton, blue-gill sunfish, large-mouthed bass, and great-blue heron. Humans are consumers who often eat both vegetable and animal matter, and are known as omnivores. Detritivores are another consumer group comprised of organisms which feed on dead organic matter such as detritus.