10, you wouldn't hear that airplane. it lives in mid we were states living underground on tree routes counting the seasonal cycles of those trees and coming into the light only once every 17 years to fascinatent model gists in the right place at the right time. >> can i qaeda periodical masih mergences are one of those ones or twice this a lifetime type of things. enjoy the show. >> reporter: in busy areas, a million and a half could appear per acre, 1 trillion in all, raising when the soil temperature reaches 64 degrees. are they dangerous? no, although they can damage trees where they lay their eggs. are they edible? >> yeah. >> there are videos on line offering recipes. like this one from the teb ten farm bureau. >> i eid eat the eyes too,