Mutualism is a symbiotic relationship in which both species benefit. A common example of this as the Alligator and the Plover bird. The Plover bird extracts nourishment for the Alligators teeth and the Alligator gets a free teeth cleaning.
I recently had my own experience with mutualism.
Last summer I was walking down my alley when I happened upon a baby bunny. His natural defense was to remain perfectly still which he did while I knelt down beside him to take a photo. While I was down next to him I said, "You look very tasty, I think I should have you for dinner." To that the rabbit replied, "I am so small I would hardly make a dent in your hunger, you should wait until I get bigger before you eat me." This made perfect sense to me and I went along my way.
Every spring I plant Morning Glories along my fence and I leave the vines on my fence through the winter on purpose because it becomes an important food source for the local rabbit population when most of their food supply is buried under the snow.
The hook is ready.
The fly is complete. This one fly will catch so many trout that will feed me for so many delicious dinners. I am glad I let the rabbit live.
Dinners are great but breakfasts are better. I'm kookoo for rabbit pellets!