This came up over the weekend. I brought a package in and a few hours later there were some presents under the tree. "Who brought those presents?" the kid asked. "Fedex brought them." "I'm going to clip her up." (Note: "clipping up" is a positive reinforcement at the kindergarten -- get clipped up a few times, and you get a prize from the treasure chest.) But a little while later, he asked me if Santa hadn't really brought them. I equivocated, but it became obvious that he understood pretty well that Santa is in the same category as the talking Frog and Toad. He wants the story, so I'll give it to him. But I won't use it as a deceitful mechanism of threatening consequences for misbehavior. At least, not if I can come up with something else that works.