For example, when Jaela lost the last tooth, they asked if I had seen the Tooth Fairy, because they figured out that she came while Mike and I were still up. I told them no, but I saw her shadow. (They have a bright nightlight that casts some pretty awesome shadows at night.)
We have also discussed (ad nauseum!) that sometimes the Tooth Fairy wears dresses (but NOT rainbow ones, sorry Macey!), every Tooth Fairy looks different, the Tooth Fairies that visited Mommy and Daddy were not the same one, and that the Tooth Fairy that visits them is not the same one that visited Mommy or Daddy. Every family has their own Tooth Fairy, and she lives in their house with them, and Jaela, Macey, Anya and Isaak's Tooth Fairy's kids will be the Tooth Fairies for Jaela, Macey, Anya and Isaak's kids. And on and on and on and on.
They have spent hours in the last few weeks plotting out elaborate plans of how to catch the Tooth Fairy at work, and see what she looks like. Yesterday they asked me if the Tooth Fairy was going to come at nap time.
Me: No, the Tooth Fairy only comes at night. She's too busy during the day.
M: What does she do all day?
Me: I don't think I can tell you that, or you'll figure out how to catch her for sure.
M, J, A: Pleeeaase, Mommy?
Me (finally giving in): OK, I'll tell you. She does her Tooth Fairy laundry, cleans her Tooth Fairy house, and teaches her Tooth Fairy kids.
J: Ooh! Thank you, Mommy!
M: Now we know where to look for her!
They spent the next 30 minutes running around the house, looking in every corner and hiding place they could think of, calling, "Tooth Fairy, where are you? Are you cleaning?" Eventually they gave up, and went to go make a place for the Tooth Fairy to live in their dollhouse. :)