Evening, our 18 month DD has recently started waking late evening, giggling, chatting and almost shrieking, really quite loudly. When we go in to settle her, it's almost as if she's oblivious to us being there - similar I suppose to night terrors(?). This may last up to 1-2 hours before she eventually self settles and goes back to sleep. She's also very recently 'self dropped' her daytime nap i.e. resists all methods! It's a little disconcerting and just wondered if anyone else has experienced this? Thanks in advance.