Why and how do body parts itch? Why does it feel good to scratch an itch?

12 Causes Of An Itchy Scalp, According To Dermatologists

Itchy Skin: 11+ Causes, Pruritius Remedies, Diagnosis Steps

Does scratching an itch provide the body with any biological benefits? - Quora

What exactly is an itch, and why do we get itchy? — Today You Should Know

抓痕的迷思！為甚麼抓痕會愈抓愈癢？, 8杯水Meditorial.co

Why is it healthy to scratch your butt? - Quora

Itches On Each Part Of Your Body Explained

Itchy Lower Legs Causes & How To Get Relief for Lower Leg Itch

Itchy Scalp: Causes, Treatment, and Prevention

Why do I get an itch and why does scratching it help? - Quora

Why can't you stop scratching an itch?

Why does scratching your head feel so damn good?, by LW, Sharing Science