Possible reasons for not laying?

[FrenchHen]

Molt. Stress. Heat. Any others?

My girls have taken a second vacation. 'Snot hot, they already molted (most of them) and there's nothing new in their pen.

 

[Elite Silkies]

Do mites and lice keep them from laying? Other than the things you already have listed, I can't think of any others, except maybe worms. But, I am really new to chickens and still learning alot........

 

[cybercat]

Up your protien it will give them a boost. Try cat or dog dry food if you can not find a better than 17% chicken feed. This works everytime as most chicken feed are too low on protien.