So I know lots of toddlers wake up early but my DD has a new habit (last few months) of waking in the early hours and screaming inconsolably. She is now 16 months and sleep in general is not great, but I have no idea what is causing this latest phase. Between 4am and 6am she wakes up screaming. If either me or DH pickles her up she writes around & tries to get out of our arms. If we place her on the bed she rolls around arching her back and rolling from side to side screaming hysterically. The other morning we gave her some milk, she drank all of this and went back to sleep until 6:30. This morning I changed her nappy. She calmed down and went back to sleep again. I don't understand what is causing this and it is quite distressing as she won't be comforted at all. Any ideas??