Sure, but they don't consciously choose to do it. Fungus doesn't decide that it's going to make life miserable for the plant it's growing on, a tall shade tree doesn't decide to starve the smaller plants beneath it of sunlight. We're unique in our capacity to see a possible course of action, do an in-depth analysis of the effects that it will have, see every foreseeable shitty outcome, and decide, consciously, to do it anyway.