This is a very short, repetitive (apologies), video (actually an animated .gif) of a mother carrying her kitten by the scruff. It is pretty plain but it has one quality: it shows the behaviour very clearly and it is sort of cute.
When the mother grasps her kitten in her mouth by the loose skin at the back of the neck (the scruff of the neck) the kitten is ‘programmed’ to go limp and passive with hind legs curled up. This is nature’s way of enabling mother to move her kittens more easily without interruption.
You may have seen people on video placing a clothes peg onto a kitten’s scruff whereupon he or she drops to the ground as if poleaxed. It’s that ‘kitten response’ again. Although I disapprove of doing this for the cameras.
The Thundershirt (a pacifying or calming cat and dog garment) creates a similar reaction in a cat. Perhaps the designers of the product built it around this well-known phenomenon.
Cat harnesses can also cause cats to collapse to the ground for the same reason. It makes walking your cat distinctly tricky if not impossible. Although cats get used to harnesses and get over the kitten response reaction in time.
