Strange ticking sensation in/on head?!

Does anybody else, like me, get this strange tickling sensation on/in your scalp? It's not a bad feeling, it's actually quite pleasurable and relaxing. It's usually on either side of my head, in the middle of the area between the ear and the back of the head.
I usually get it in the afternoon or evening, when sitting down or lying in bed. I have also noticed that I get it when listening to someone who is well spoken, or a quiet piece of music.