Landowners north of Boulder have been using an explosive, state-approved device to blow up prairie dog holes -- and some of their neighbors don't like it. The Daily Camera reported Thursday the Colorado Wildlife Commission approved the "Rodenator" in 2006. It explodes burrows by igniting a propane mixture pumped into the holes.Propane is heavier than air, so it sinks into the burrow system, and ignites safely underground, according to a Colorado company that uses the system. Nearby residents who live in the city have complained the method is cruel, inhumane and extremely loud. Some have reported seeing prairie dogs on fire. Boulder County sheriff's officials have estimated the explosions exceed the county's sound limit of 50 to 55 decibels. Employees at a ranch where the device is being used says it isn't meant to kill the animals. It's illegal to use the Rodenator in Boulder, but not in the county, where the ranch is. The device is used around the world and costs $1,690, according to the Idaho company that sells it.The company claims the Rodenator has been used on voles, moles, gophers, ground squirrels, prairie dogs, rabbits, armadillos, marmots (rock chucks, ground hogs, wood chucks), badgers, foxes and coyotes.A number of videos have been posted on YouTube showing the Rodenator used on burrows.