I have a hen (pretty sure it's just one) that lays eggs with what appears to be sand on the shell, but within the shell. It does not rub off.
Does anyone have any ideas on what this is? Is it something I should do to try and fix it, or is it ok?
The rough texture of the eggs can be caused by too much calcium. They also can be caused by rapid changes in lighting. It can also happen when they're is a disturbance to the hen when she is going to lay and the egg is held over for a bit. It is not usually cause for concern. Occasionally these types of eggs happen.