When you have hens for eggs, it's not unusual to lose some and need more. With an existing flock, we have always found it easier to use a "hen-powered incubator and brooder" rather than having to fuss with lights and such. The hen that is broody and sets out proves to be a good mom and takes care of those little "biddies" really well!
Though several times we were fooled and given up hoping for an increase this year, one of the black dorkings accepted a nest a few weeks ago. Starting with 14 eggs, two of which were broken when she was spooked off the nest, she sat on those 12 eggs until yesterday, when her lumpy bed started making noises! Yesterday, four chicks were seen and she remained on the nest. This morning she left the nest, one egg remains. Somehow they know which eggs will hatch or not. . .
In the past, it has seemed like so much less hassle to let the hen do the work. Typically, they will not nest until it is warm enough. This is a bit later, we have usually seen end of June for hatch. Either case is often much later than the chicks arrive by mail and such a struggle to keep warm when the weather is still cool!
Do you believe the old adage that round topped eggs are hen and pointed ones are rooster eggs? Sorry to say, there is no truth to this matter. We did find this reference, the-secret-to-hatching-hens-not-roosters, which talks about using refrigeration to cut down on the number of rooster eggs that hatch. Adding our own experience, we decided since hen chicks are smaller that rooster chicks, we would try setting the smaller eggs, not the largest ones laid. It will be a number of weeks until we know if these efforts have succeeded in more hens - which is really what we want - to increase our egg count!