Field trials were conducted to test the effectiveness of a gas exploding device called ''Rodentorch" in reducing pest populations of ground squirrels and prairie dogs. Ignition of a propane/oxygen mixture injected for 30 seconds into burrows reduced prairie dog activity 13.0%. Doubling the injection time in prairie dog burrows to 60 seconds resulted in a 63.3% reduction. Reduction in ground squirrel activity was 40.6% after a 45 second injection time. Comparative trials on ground squirrels using EPA registered gas cartridge and aluminum phosphide fumigants resulted in 90.8% and 83.7% reduction in activity, respectively.