WATCH HERE WATCH HEREJack Klaas, along with brothers Jake and Nick Ironfield, are behind "Greenhead Guys" making a plant-based and safe repellent. Greenhead Guys' plant-based, DEET-free spray hit the market this year after extensive research, formulation and testing. “It also works extremely well against mosquitoes, ticks, gnats, deer flies, horseflies, no-see-ums and other biting insects,” Ironfield said. The demand has meant long days for the Greenhead Guys. The Greenhead Guys are now looking for commercial space as they plan to expand the business.