Invasive species help the ecosystem by killling a certain animal. If the invasive species doesnt end up eating it, decomposers will decompose it and therefore make more soil/dirt for the environment. Also, if they keep eating a certain organism then the organism that eats that organism can learn how to adapt into eating a healthier species of organisms, or they could move to a new area bringing more life to it. Hope that helped! And hopefully you get what i'm trying to say.
