The term “hornet” has a technical meaning, and Iowa has only one species of hornet – the bald-faced hornet, which has black and white stripes and a white face. Bald-faced hornets aren’t aggressive and typically stick to wooded areas, where they make large, spherical paper nests, Donald Lewis, an Iowa State University professor of entomology, said. What Iowans are observing this spring are likely wasps and not hornets, Lewis said. There are two species that are active in the springtime – paper wasps and yellowjacket wasps. Paper wasps have long, slender brown bodies.