My friend's DD (3.10) still occasionally has a dummy. Last week she was upset before she went to nursery and asked for it. Her mum had tried to get it off her before she went into nursery but she got upset again so she let her go in with it. When she went to pick her up her DD was hysterical because the staff had taken it away from her as soon as she walked in the door and wouldn't let her have it back. They told her off, made her sit in the naughty spot and put a sad face on the behaviour sticker chart.