(Radio Iowa) – One of the experts in all things creepy-crawly who helps to run Iowa State University’s Insect Zoo just returned from a four-day road trip exclusively to study the rare, double-brood emergence of cicadas. Ginny Mitchell, the I-S-U Insect Zoo’s education program coordinator, says the 13-year and 17-year cicadas are coming out of their underground burrows simultaneously, which only happens once in every 220 years.

Mitchell says the 17-year cicadas can be found in northeastern Iowa along the Illinois border, while the 13-year cicadas are in southeastern Iowa, along the borders with Illinois and Missouri. Their song can be almost deafening, as some estimates say there are perhaps trillions of the bugs emerging across the region.

The inch-long creatures that are appearing now are relatives of the ones that will start buzzing across the rest of Iowa within a few weeks.

Another difference in the three-year versus the 13- and 17-year cicadas is what time of day they choose to make themselves known.

On her road trip, Mitchell says she collected hundreds of both 13- and 17-year cicadas, including adults and nymphs. She plans to cook, yes, cook a variety of them for visitors to sample during the I-S-U Insect Zoo’s “Bug Village” event on August 24th. It will also feature a class called Insect Collecting 101, a Bug Costume Contest, and more than 150 species of living arthropods on display, with plenty of hands-on opportunities.