A chicken can be hypnotized, or put into a trance, with its head down near the ground, by drawing a line along the ground with a stick or a finger, starting at the beak and extending straight outward in front of the chicken. If the chicken is hypnotized in this manner, it will continue to stare at the line, remaining immobile for as long as 30 minutes. Other methods of inducing this state are also known. Ethologists refer to this state as 'tonic immobility' i.e. a natural state of semi-paralysis that some animals enter when presented with a threat, which is probably a defensive mechanism intended to feign death, albeit rather poorly. An early reference of this phenomenon was described in 1646 in Ars Magna Lucis et Umbrae by Athanasius Kircher. Methods One technique of hypnosis is to hold the chicken face up with its back on the ground, and then run a finger downwards from the chicken's wattles to just above its vent. The chicken's feet are exposed, which allows easy application of medication for foot mites, etc. Clapping hands or giving the chicken a gentle shove will waken it. One can also hypnotize a chicken by mimicking how it sleeps – with its head under its wing. In this method, the bird is held firmly, placing its head under its wing, then, the chicken is rocked gently back and forth and set very carefully on the ground. When this is done it generally stays in the same position for about 30 seconds. H.B. Gibson, in his book Hypnosis – its Nature and Therapeutic Uses, states that the record period for a chicken remaining under hypnosis is 3 hours, 47 minutes. Notable practitioners Al Gore, former U.S. vice-president, Nobel Peace Prize winner, and ex-presidential candidate, said that people in his native state of Tennessee would sometimes hypnotize chickens by placing the chicken's head on the ground and drawing circles around it with a finger or a stick, causing the chicken to try to follow the motion. Werner Herzog was "known to hypnotize chickens; he also hypnotized the cast of his 1976 film Heart of Glass". Steve Fairnie, a 1980s British musician, advised: "You have to dominate the chicken and be right above it staring into its eyes. Then it will either go under or it will viciously attack you, so you have to be a bit careful...". In popular