So my 5 hens are not quite a year and a half old. They eat an all flock feed with free access to oyster shell and crushed egg shells. And yet, their shells are consistently thinner than even a grocery store egg what gives? Are there other health problems that might cause thin shells? I plan on worming them this week because I haven't before, and because I feel like egg production had slowed. It's been really hot lately, so I know that's at least part of it, but I just want to be sure it's not something my inexperience is causing me to miss. They seem to be eating and drinking fine, so I'm stumped... Thanks!