In the rain forest, arthropods are known to lay their eggs in the feces of sloths, providing food for the growing larvae. This is a perfect example of commensalism.
Commensalism occurs when one organism in the relationship benefits from it, while the other is neither hurt nor benefited. Another example would be a frog living under a plant for cover. This relationship does not affect the plant in any way but provides the frog with the shelter it needs. Commensalism differs from mutualism, which benefits both parties involved, and parasitism, which is beneficial to the parasite and harmful to the host.