Goats known as "fainting goats" don't actually faint. Instead, they have a hereditary condition called myotonia congenita. This condition causes their muscles to stiffen suddenly when they are startled or excited, which makes them freeze and sometimes fall over. They remain fully conscious during this episode and do not lose awareness. The muscle stiffness usually lasts for about 5 to 20 seconds before relaxing again. Myotonia congenita is caused by a genetic mutation affecting chloride channels in the muscles, which impairs the muscles' ability to relax quickly after contracting. This leads to a temporary rigidity that results in the goat falling over instead of fainting from fright. This condition is not painful for the goats, but it can make them vulnerable because they cannot run away from threats while stiffened. In summary, fainting goats "faint" due to a muscular disorder rather than loss of consciousness, and their falling over is caused by a delay in muscle relaxation when startled.
