UFO Files: Cattle Mutilations
Various hypotheses suggest cattle mutilations have been committed by aliens gathering genetic material for unknown purposes. Most of these hypotheses are based on the premise that earthly entities could not perform such clean dissections in such a short space of time without being seen or leaving evidence behind at the mutilation site, and around laboratory reports suggesting the use of unconventional cutting tools and other unexpected phenomena. Numerous speculative theories abound, but others center on possible specific nutrient requisites, hormone procurement, species propagation (reproduction), and rote experimentation on mammalian population.
Since the time that reports of purported animal mutilations began, the causes have been attributed variously to natural decomposition, normal predators, cryptid predators (like the Chupacabra), extraterrestrials, secretive governmental or military agencies, and cults. "Mutilations" have been the subject of two independent federal investigations in the United States.
Black helicopters is a term which became popular in the United States militia movement and associated political groups in the 1990s as a symbol and warning sign of an alleged conspiratorial military takeover of the United States, though it has also been associated with men in black and similar conspiracies. Rumors circulated that, for instance, the United Nations patrolled the US with unmarked black helicopters, or that federal agents used black helicopters to enforce wildlife laws. The concept springs from the basic truth that many government agencies and corporations do use helicopters, and that some of these helicopters are dark-colored or black. For instance, dark-colored military helicopters were deployed in the standoff at Ruby Ridge.
Metonymic use of the phrase black helicopters sometimes occurs in reference to conspiracy theories in general.