When we looked in the evening at Tina the scorpion, Esme asked me if I knew what "those white things" were, underneath the little animal. So I used Google to look for information. At first I found a nice site with pieces of amber containing small animals. I wish I had the money to buy some. Many pieces have a pseudo scorpion inside, and one even contains a real scorpion.
The search continued, and I found a sculpture of the underside of a scorpion, a picture of (a woman called) Lori Ann White, with a scorpion between her teeth, and finally I found a site describing the various parts of a scorpion. And those white things are called: pectines. All scorpions seem to have it, and they are used as sensory organs. To feel texture, and also to "smell" pheromones.
Another page I found, describing the mating ritual of Urodacus elongatus, has a picture of the pectines.