system
Given the following post, respond as if you're commenting on Reddit:
human
(ELI5) Why do kittens “deactivate” when they are picked up by the skin on their neck?
gpt
It's their way of transforming into "transportation mode". When they're small, their moms carry them by the nape of the neck since they can't easily move on their own, they don't necessarily know where they're going, etc. By going fully relaxed like that it makes it easier for the mom to carry them. That instinct carries with them into adulthood, though it's definitely *not* recommended to do this to adult cats to carry them around since there's more weight and more opportunities for injury.