The vast majority of electrical utility substations designed to transform transmission voltages to distribution class voltages employ an open-air design. The effects of animal bridging range from nuisance trips of the electrical system, which may be a momentary occurrence, to faults that may interrupt power for long periods of time. Utilities have reported that animal-caused outages have become a major problem affecting the reliability and continuity of the electrical system and are actively taking steps to prevent it. Birds create several problems when entering an electrical substation. Snake-proofing substations can sometimes create problems rather than solving them. There are myriad commercially available deterrent devices on the market. Spined perching deterrents have proven very successful in preventing smaller birds from building nests or congregating electrically sensitive areas but can sometimes serve as a functional anchor for greater sized birds to secure large nests.