A scavenger is an organism that consumes dead and decaying plant and animal matter. Scavengers do not hunt and kill their food, but rather eat animals and plants that died by other causes. One of the most recognizable examples of a scavenger is a vulture. Earthworms are also scavengers, moving through the dirt eating dead plant and animal material found in the soil.

Some scavengers only consume dead plant matter, while others eat only dead animals. However, many consume both dead plant and animal matter and therefore are considered omnivorous. Other organisms will only scavenge for their food some of the time. For example, a crab will eat an already dead organism if it comes upon it. Yet other times the same crab acts as a predator, actively hunting for a live clam or mussel to eat. Crows are also only scavengers when dead meat is available. They will eat dead animals on the side of the road that have been killed by cars, but they will also eat farmers' live crops.

Because scavengers are not able to make their own food, they are considered heterotrophs. They must obtain all of their nutrients and energy from the food they consume.

Scavengers play a very important role in food webs. They are an important link between the producers and other consumers and the decomposers. Scavengers are an important first step in the recycling of nutrients back into a form that plants can use.