Cats have a high need for tickling, and itching is unavoidable for animals that do not take the initiative to bathe. In fact, not only cats, dogs, and even pigs have a need for tickling. My personal experience is that the old sow at home once gave birth to a litter of piglets. My sister and I prefer the smallest one among them, and we often scratch it when we have nothing to do. Itching, and later developed to the point that as soon as I touched it, I would lie on the ground with a plop, stretch out my limbs, as if I was coming to scratch it for the uncle.
Cats usually like to scratch their necks with their hind legs. According to my own observation (without theoretical support), the neck area of cats should be the place where itches easily. Just this pose:
Scratch behind the ears at most,
It can be seen from the cat’s leg structure