Answer:
By having more animals that eat plants you must keep the food chain at a minium or else the predators or prey will take over the food chain and it could cause a lot of problems. Using herbivores will not only help us but help the plants once the old plants die or get eaten they can grow knew ones and the cycle repeats itself. OR Humans can use some chemicals on the plant's roots to stop the growing but if you do that, that can be even worse because we need plants to survive. Plants helps us breath by filtering out the pollution and give us breathable oxygen. So in order to keep the plants from invading/spreading animals can help us because they don't kill a lot of plants they just eat the ones that are there.
Explanation:
