I think it`s just a bad habit and I don`t allow it. Luckily it hasn`t been a problem as of yet...noone`s asked me to. If it were to happen I`d hope that the parents would be on board to break a bad habit the earliest possible. If not, I would still not allow. They`re smart and understand what is acceptable at home and at daycare. Some parents rock their kids to sleep, I simply place them down and won`t do more. They get used to it, even if the parents continue to put their kids to sleep at home.