Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: In grazing , the predator eats part of the prey but does not usually kill it. You may have seen cows grazing on grass. The grass they eat grows back, so there is no real effect on the population. In the ocean, kelp (a type of seaweed) can regrow after being eaten by fish. Answer: prey
A:
In grazing, a predator partially eats but does not kill what?