Last trip we all had APs, me, DH, DD12 and DD9. My older DD had an "adult" ticket and so she had to do the bioscan, along with me and my DH. My younger daughter must have felt left out because each time she put her ticket through she pretended to do the bioscan. (She actually put her fingers on the scanner, it just wasn't reading anything.) She loved it and thought it was cool. I don't think it seems scary at all. But she isn't one to be normally scared easily.
Maggie