Taming baby budgies in the nest?

There are 2 baby budgies(2 weeks old) in the nest with the parents. And when their eyes started to open I started handling them a little bit each day. Now they are 16 and 15 days old. When I go to handle them now, they are scared and one of them tries to bite me and squawked at me. The only thing is I don't know what I did wrong. I am very gentle when handling them and never did anything that should scare them. The parents are untame but never try to bite me. I was hoping they would be tame when they were older but it seems they are just very scared of me and i don't even know why. Please help! Thanks!