How does a squirrel help the world?

Squirrels include insects in their diet. They thereby contribute to the control of insects that feed on tree parts. They also bury nuts. They thereby contribute to the growth of trees, and to forest cover. They eat the nuts that they don't bury. Among their favorite snacks are black walnuts. They thereby help keep the area under black walnut trees picked up. And so people have an easier time walking barefoot, running, or bicycling. And squirrels help keep the environment friendlier in the area. For black walnut trees are allelopathic, which means that they emit the chemical juglone, which is hostile to the growth of many herbaceous and woody plants. By eating the nuts, squirrels decrease the amount of juglone at a given time, and in a given place. And squirrels are a delight to watch in parks. They thereby contribute to the leisure time enjoyment of park visitors. And they also run races with dogs. They thereby contribute to canine health, because dogs get their exercise in for the day.