What drive would scavenging be, food? Wouldn't food drive just be a derivative of another drive, say prey? But if its already dead, how could it be prey drive when it isn't moving? I know the search for food is from the drive to survive, but that's too simple. I've had dogs who turned their noses up to raw meat or even carcasses, and the dogs I have now most deffinitely look for carcasses to roll in and consume.