Me too .... I have a 13 month old shrieker ..... I think its a " your not looking at/paying 100% of your attention to me" shriek. It's seriously grates on my last nerve too. Thank god she still naps twice a day and I'm not encouraging her to give it up anytime soon ..... I'm sure it has to do with the lack of vocabulary but she is rather chatting in her own language .... So I'll take some advise too