In a food chain, energy is passed through one link to another. When a herbivore eats only a certain fraction of the energy, (which comes from the food) it becomes new body mass; the rest of the energy is lost as waste or used up by the herbivore in order to carry out its life processes (ex. movement, digestion, reproduction). It doesn’t necessarily threaten the plants survival, there’s also a benefit. When a animals poops out the fruit (defecate) in another area those seeds get carried to new places with the help of a dab of fertilizer and a little bit of moisture. They also help supply nutrients when they die and decompose.
