This afternoon I was cleaning out the poop from the droppings board and I found this (egg shown for size comparison):

It resembles a date, but is much harder. While I was pretty certain it was not a date (I don't know how one would have ended up in the coop), I cut it open to be sure:

Definitely not a date. My googling has turned up no information as to what this may be so far. Has anyone here ever seen anything like this before? I have four hens that are about three years old. They have all been molting, but look to be about done, and one of them has a slightly pale comb. Their egg production has been way down, because of the molting and winter, I assume. I've also been getting a lot of broken eggs with very weak shells for the last two months or so, even though I mix in oyster shells to the feed in the same ratio I always have. Outside of these symptoms, I haven't noticed anything else out of the ordinary.
Here is an album with a few more pictures.
It resembles a date, but is much harder. While I was pretty certain it was not a date (I don't know how one would have ended up in the coop), I cut it open to be sure:
Definitely not a date. My googling has turned up no information as to what this may be so far. Has anyone here ever seen anything like this before? I have four hens that are about three years old. They have all been molting, but look to be about done, and one of them has a slightly pale comb. Their egg production has been way down, because of the molting and winter, I assume. I've also been getting a lot of broken eggs with very weak shells for the last two months or so, even though I mix in oyster shells to the feed in the same ratio I always have. Outside of these symptoms, I haven't noticed anything else out of the ordinary.
Here is an album with a few more pictures.