This Earth Day, we are mindful of two of nature's marvels at school. The first is the power of compost worms in our compost bin, producing the super dirt for our garden out of our (selected) trash. They are tireless and obliging workers! Secondly, the swallows have returned! A couple built their nest under our back eave last summer. Our reading tells us they traveled to the Philippines for the winter. Either the parents or their offspring have come back to their very nest. Whew! Swallows are quicker and harder to photograph than worms are, but we have two mind-boggling details of our natural habitat, Earth.