Just returned from 10 days at WDW. my 4yo ds did NOT have to have his fingers scanned. However, when we upgraded from AP's to PAP's we did not at first catch that his ticked had been changed to an adult one. Even though he was obviously not an "adult," we had to lift him up to have his finger scanned so we could get to Guest Services at AK (It was evening EMH.) and have his ticket fixed.