Should be a tag sewn into bottom of feed bag listing the percentages and ingredients.
Coop size looks about right, should be good space for 9 birds.
How long have they been doing this?
Gather often and leave fake eggs in nests.
First, need to find out why, so some info please:
-your flock size(numbers, ages, genders)?
-your coop(size in feet by feet with pics)?
-and what and how exactly you are feeding?
Are you finding just a wet mess or is the shell still there?
Is the shell thin or soft?
Fake eggs can help...