Pashun George and her sister grew up scratching their mother’s back before bed. Now, they charge $130 an hour for it. In 2010, they turned the tradition into a family business, Scratcher Girls, the ...

Scratching an itch can bring a contradictory wave of pleasure and misery. A mouse study on scratching, reported in the Jan. 31 Science, fleshes out this head-scratching paradox and could point out ...