thanks everyone. I'm back online. after posting this morning, I searched for more info on this site and found info on emergency intervention when necessary. our situation seemed to warrant us helping the chicks hatch because the membranes on our eggs are really, really tough. so weird that they were able to get the shell off but not the membranes. so we realized that we definitely have issues with tough membranes from our own experiences when we've cracked open fresh eggs and hard-boiled eggs to eat.
that said, my husband went out and pierced the membranes on the three eggs you see in the photo that had pipped the shell and out came two live chicks! sadly, one little chick had already smothered and died. very, very sad. but thank goodness he saved the others.
with that success, he went ahead and did "zippers" around the top of each shell that was pipped as decribed in another post on this site. by 2 p.m., we had five healthy, thriving chicks and had lost one more chick, which was perfectly formed but dead in its shell. so sad.
but by 8 p.m. we had eight healthy, peeping chicks and there were two shells left, one without any cracks or pips and one with a little beak sticking out. I am home alone this evening so I used my husband's "zipper" technique around the shell with the beak sticking out and I put the egg back under the momma hen. I hope to go out tomorrow and find at least nine healthy baby chicks. and maybe that 10th egg will have a pip in it by then, too. I hope so.
so far, 8 perfect chicks out of 12 eggs and 2 chicks that we lost. I'm so glad that we did intervene or we would have lost at least two more and possibly all of the little chicks.
does anyone know what causes such tough membranes? we're wondering if we need to change up the feed that we give the hens.