A bug expert is teaching four Iowa school districts how to stay cleaner and avoid pest infestations. I-S-U Extension entomologist Mark Shour is running workshops for school personnel, including principals, nurses, custodians and cooks. Instead of spraying pesticides, Shour says people need to re-learn how to keep their schools bug-free without using hazardous chemicals.They’re being told to do things like put up window screens, put new brushes on doors, caulk around pipes, and move garbage bins away from doors. He says even cleaning more often can help get rid of pests.Shour says pesticides should be the last line of defense from bugs as he says a little bit over a long time could be hazardous to staff and students. The schools taking part are: Davenport Community, Lewis Central, Sioux Central in Sioux Rapids and Woodward-Granger.