I only do parties if a child is leaving to start school as in it becomes the equivalent of a preschool graduation for them. I give them a certificate, we do a special snack and I give them a gift. I also will do something similar for a child that is moving to a new city such as a military family that is transferred and then it is more to have something special to remember a phase of life that is now over. For other reasons it is simply special cookies at snack as in acknowledged but not a party. Even if parting is on a sour note I figure the cookies help for all of the kids in the daycare group non of which understand why the child is going including the child themselves. Same for those that are leaving for other reasons. Even if I do understand it is because of a new house or mat leave or whatever it is like a part of me doesn't feel they get the over the top party cause it is the parent making the decision to pull the child not extraneous circumstances like age or transfer.