There are three types of symbiotic relationships that occur in the desert: mutualism, commensalism and parasitism. Examples are, respectively, yucca plants and yucca moths, dung beetles and the dung of other animals, and fleas and their hosts.
Symbiotic mutualism occurs when both parties benefit from the interaction. In the desert, the yucca moth and yucca plant are mutually symbiotic. The yucca moth pollinates the yucca plant by carrying its pollen from plant to plant; in return, the yucca moth lays eggs and lives in the yucca plant.
Commensalism describes a symbiotic interaction in which one party benefits and the other is unaffected. An example is dung beetles, which live off the dung produced by other animals. These dung-producing animals neither benefit nor are harmed by the dung beetles.
The last type of symbiosis is parasitism, in which one party gains through the interaction and the other is harmed. In the desert, fleas live on coyotes as parasites, thereby gaining both a food source and a home. This interaction is parasitic because the fleas are harming the coyote's health. Another example of parasitism is the praying mantis and the wasp. The wasp lays its eggs inside the praying mantis's eggs, and when the wasp larvae hatch, they feed on the praying mantis eggs.