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 and remain 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.[1][2][3][4]
^Gallup, G.G., Jr., Nash, R.F., Potter, R.J. and Donegan, N.H., (1970). Effect of varying conditions of fear on immobility reactions in domestic chickens (Gallus gallus). Journal of Comparative and Physiological Psychology, 73: 442–445
^Gallup, G.G., Jr., (1979). Tonic immobility as a measure of fear in the domestic fowl. Animal Behaviour, 27: 316–317
^Jones, B. and Faure, J.M. (1981). Tonic immobility ("righting time") in laying hens housed in cages and pens. Applied Animal Ethology 7: 369–372