The premise of effigies, pyrotechnics, and propane exploders is that there be a perceived immediate danger to the species to be dispersed. Initially, the sight of an unnaturally positioned effigy or the sound of pyrotechnics or exploders is enough to elicit a danger response from wildlife. As wildlife become habituated to non-lethal methods the culling of small numbers of wildlife in the presence of conspecifics can restore the danger response (Baxter and Allan 2008, Cook et al. 2008, Commander, Naval Installations Command 2010, DeVault et al. 2013).