What are feeders, and how do the others at the academy feel about them?

Feeders are humans who allow the Moroi to feed on their blood. The Moroi do not kill their victims, and the feeders are addicted to the effects of the vampire saliva. Both the guardians and the Moroi vampires at the academy look down on the feeders as addicts. They only allow the feeders to be around because they need to feed on them.