My 16 mo DD has suddenly (over the last week) decided she does not like going outside in our garden. We went on holiday 3 weeks ago and she was fine before then and fine with being outdoors whilst we were away. However since being back home, she suddenly does not like going outdoors. Whereas before as soon as the door opened (front or back) she was out there before we could stop her, now she just looks at it and says no and tries to close the door. We were with friends yesterday and she was fine walking in and out of their garden but today when I put the washing out, she just screamed and screamed the whole time and clung onto my legs. There is nothing scary that I'm aware of in the garden and nothing scary has happened to her in the garden either. Nursery have also commented a bit that in the last week particularly she has been scared of the helicopters going overhead and of the lorries or motorbikes going by outside. They are managing this though by encouraging her to wave bye bye to the helicopters etc. I'm just puzzled by where this strange and intense dislike of the outdoors has come from and don't know what I can do to help her get over it. Any suggestions?