Electromagnetic, sonic, and ultrasonic devices claiming effectiveness in controlling rodents and other pests have seen resurgence in the marketplace. Laboratory and field tests of such devices have generally failed to show they are effective, despite advertising claims. Rodent burrow exploders have been marketed for use against pocket gophers, ground squirrels, prairie dogs, and other burrowing rodents since the 1980s. Field tests indicate these exploders are expensive to use and typically provide unacceptably low efficacy. Vehicle-mounted devices to scare deer off roadways, with many claiming to generate ultrasonic sound, have been widely sold. Studies reveal that deer are unable to hear ultrasonic sound, and that the devices appear to have no effect on deer behavior. While Federal regulatory agencies have authority to prohibit false and misleading statements in advertising of such devices, enforcement actions and scientific testing on which regulatory actions are based are expensive and time-consuming, and agencies are resource-limited
