DD just refused to sleep in the cot at 16 months old. Took me a few nights to realise what the screaming and no sleeping was for, but once we'd borrowed a foldout bed to see how she'd go, we never looked back. She was nearly too long for it anyway at that age.

DS has never slept in a cot he hated it from the get go. He went into his own bed (more often than not slept in by DH but hey ) from ours at 10months.