Yes, I think they must know he is not like other 2.5 year olds...it is quite obvious and becoming more so the older he gets. My neighbour who is a daycare provider can see it too and said she has a hard time believing the parents don't know. I am proceeding cautiously...not using the word autism...but trying to push some of the concerns more now. They think it's just language, but it truly is not. He is so hugely different even from the 20 month olds in my care...I know the parents don't have that comparison and I want to make sure I tell them. If they still don't do anything there is nothing I can do, but I have to know that I did what I could. If they leave my care because of it, so be it. I truly care for this child as he has been with my since he was 9 months old and would hate to lose him, but I can't sit by and do nothing.