Animal hypnosis also termed tonic immobility or reflex immobility is a behavioural state in which the animal is both immobilized and more or less unresponsive to most of physiological stimuli. The effect has been observed in many different species including birds and mammals. It occurs spontaneously in the wildlife as for the so-called feigning death, playing possum, fascination etc. It is considered as a survival strategy. It is likely due to a large release of endorphins by the hypophysis explaining that tonic immobility is associated to analgesia and drowsiness. It can be obtained experimentally using various types of physical stimuli (kitten becomes quiet when their mother grasps them by the neck), tools (as clip for cats, nose twitch for horse etc.).
Cattle and calf during clipnosis
1- To see how to proceed, click on this 5 min video tap (in french) showing how an adult dairy cattle can be immobilized using surgical clips, fall down spontaneously and became totally unresponsive allowing to be placed on dorsal decubitus by only one person
4- More recently this technique was revisited by Pozza & al in an article entitled Pinch-induced behavioral inhibition (’clipnosis’ in domestic cats In : J Feline med Surg 2008 10 82-87