Nature Story Hour is held on the first and third Thursdays at 10 a.m. during the summer months at Leonard Grimes Memorial Amphitheater at the Grimes Farm, 2349 233rd St., Marshalltown. In the event of inclement weather, the program will be held indoors at the center. The program will start with a storybook read-aloud, an educational program by the naturalist on the topic and an activity or craft. Each session will last about 30 to 40 minutes. The July 16 topic is Bats presented by Angie Dudley, GMG teacher.