For how long were they part of the research? Most of them start laying at 20 weeks old, if thats the case that's also why your not getting that many eggs (that and being stress) thats amazing once they all laid an egg plus 2. Oh well that's nice, another thing, I suggest to clip their wings so they won't be flighty, mine are not calm but i clipped their wings at young age at feed them once a day while i stay with them and grab them once in a while one by one and see they look ok. (Just a little tip.)