Grasses and herbivores have evolved in response to each other. Herbivores need grasses for food, grasses need herbivores for fertilizer, and to trample tree seedlings that might grow near them and shade them. Give three characteristics that grasses have developed in order to withstand herbivory: 1. 2. 3. Give two characteristics of herbivores that allow them to eat grasses, that are more difficult for nonherbivores to eat: 4. 5..