I have 3 hens (about 2yrs old). We've owned them for about 7 weeks. The came with the house that we bought. Only 2 are laying. I have not seen an egg from the dark red hen. I've looked in the yard for a secret nest. Every once in a while I will find an egg laid while roosting (maybe once a week). It's always on the floor of the hen house usually without a shell, or a very thin shell. I don't think these are coming from the other 2 hens because they lay in the nest like clock work. What do I do?