to be honest i really don't know, but so many people say it's the best experience ever! i've read some things that say it might be to do with the stimulus on your back and nerves, but it's not the same as scratching anywhere else so i don't know if that's true. i've never actually had anyone else scratch my back but my best friend assures me it's blissful ^_^. she's never liked being touched at all (i'm really close to her and even then i can't hug her or rest my head against her or even trace patterns on her arm :( ) but for some reason she says she'll let anyone scratch her back because it feels so good! i can't help but imagine her stretching out in pleasure like a kitten :)
for scratching their backs
You are scratching a spot that feels good to them. You might also be scratching a spot that is hard for them to reach. Say if your cat has arthritis somewhere on their back end, they most likely can't reach their back.
Scratching athlete's foot can provide temporary relief from the intense itching caused by the fungal infection. The action of scratching stimulates nerve endings in the skin, which can create a sensation of pleasure and distraction from discomfort. However, while scratching may feel good in the moment, it can worsen the condition by causing skin damage and spreading the infection. It's generally better to treat athlete's foot with antifungal medications to address the root cause rather than relying on scratching for relief.
parietal
To see if it smells good, or not. I think that would be disturbing to see, someone scratching there crack and sniffing it.
It is not likely that scratching the 8 ball will affect your luck in the near future.
It means scratching. ( as in the sentence, when we feel itchy we may 'scratch' there)
Leopards are very good at biting and scratching.
You can prevent your cat from scratching the door to get in by providing alternative scratching surfaces, using deterrents like double-sided tape or citrus scents, and rewarding good behavior with treats or attention.
dutch saddle backs
The ancient Egyptians instead of fighting the enemy the would kill themselves.
I have this exact feeling after scratching my eczema, almost as if the patch of skin i have scratched and was so itch and uncomfertable before feels numb after the scratching, for those 5 minutes afterwards you feel relieved but then it just comes back and its worst cos u have scratched it