The Yucca plant depends on the moth for pollination, and the moth benefits by laying its eggs in the flowers of the plant. The larvae feed on the seeds, but the plant benefits from the moth's pollination. This relationship is an example of mutualism because both species benefit.
The cattle egret and grazing cattle in close association, a sight you are most likely to catch if you live in farmed rural areas, is a classic example of commensalism (one is benefited and other is unaffected).

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