Nancy Solves The Case

The Mystery of the Thin Shelled Egg has been solved by Nancy Drew, herself!



Throughout September and October, Nancy Drew laid only a couple of eggs a week, and those were thin-shelled and easily broken (and then eaten by Betsy Ross, the pesky little bantam White Leghorn.)

What caused her eggs to be so fragile? The flock’s diet is excellent, and the other hens are laying sturdy eggs, so food wasn’t the culprit. Sometime disease can cause thin eggs, but then the eggs will be wrinkly or misshapen, and Nancy’s eggs were smooth, so that lead was a dead end. Sometimes hens are genetically predisposed to laying poor quality eggs, but some of Nancy’s were fine. So, what was to blame?

Nancy Drew pondered the mystery. She sat in her nesting box and thought. She sat and thought some more. And it was that very sitting and thinking that solved the problem! It takes more than 25 hours from the time that a yolk is released from the ovary until an egg is formed and released out of the uterus. Twenty of those hours are spent in the shell gland. At the end of the process, the hen needs to sit quietly while the shell finishes being constructed. A chicken that is agitated and jumps in and out of the box, or a hen that never settles into the box, will lay fragile eggs. Nancy Drew was one of those hens. She didn’t give her egg-making apparatus enough time.

But, Nancy has learned patience and she has solved the case of her own thin-shelled eggs. She’s now laying four eggs a week, and they’re all perfect.



  1. I wonder if this is what my Barred Rock hen`s problem is? She always has been a bit of a nervous nelly and is also guilty of laying thin shelled eggs more often then not. Right now she is moulting so she has not been laying at all. I hope she solves her mystery and will be a reliable source of hard shelled eggs. I only have 2 hens laying right now due to moulting season…sure miss all the eggs!

  2. Good news. I have 8 molting now. The 9th hen finished her molt 2 weeks ago but no eggs from her as of yet.. So I am eggless in baltimore. But I am glad the girls have a chance to rest. My fried puts a light on to keep the eggs coming but I feel the girls need a rest as nature intended.

  3. Hooray! So good to hear all is well with Nancy Drew’s ‘egg factory.’ She is so very pretty in the sunlight and I’m glad to hear she did not have an internal egg problem! Congratulations Nancy Drew! Do the quality eggs Nancy lays now make it difficult for little Betsy Ross to break open and eat?

    • Betsy Ross never broke the eggs, she only took advantage of ones that were already cracked. Betsy won’t bother with the sturdy ones that Nancy is now laying.

  4. good for nancy!
    now i wonder – would she like a toy to keep her occupied while she is on – well, youcould call it maternity rest.
    maybe a plastic bug, or fake spider.
    how long does she have to sit after doing her laying?

    • Once she lays the egg she can get up and leave, it’s the time before that she needs to be quiet and not so restless. Some hens sit for about a half hour before laying, some longer. Some are very quick.

      • does this mean that if I go out in the morning when Lucy is sitting in the box, and she jumps out to greet me, which she often does, and goes back in later, that her egg shells can be thinner because of it?

        • It might or it might not. If your hen never settles in, then it will affect the egg laying. Sometimes this happens to an entire flock if a predator has been disturbing them. But, my guess is that Lucy can come out, cheerfully say hello, and then go back in happily, and her egg shell will form nice and solid.

  5. The ONE egg per day (sometimes) I am now getting is hard shelled. Our girls are flighty, but they don’t normally jump in and out of the nesting boxes. There are some that get in, lay their egg and get back out. I have a couple that seem to take hours to actually lay their eggs. It must be pretty tiring too, because sometimes they “rest” for a while after the deed is done ;-)
    Our 15 girls are STILL molting. Only one or two of them has started laying again. I decided that this winter, we would not use any artificial light with the exception of now and then adding a heat lamp if the weather is too awful. Shouldn’t happen often, hopefully.
    The coop and their pen is awash in colored feathers and with all the pecking that goes on, the Wyandottes are slower to recover their feathers. I love the markings on these GLW hens, but when this batch is done, I doubt I will ever try another Wyandotte hen.
    Glad Nancy D figured out what the problem was!!

    • It is detrimental to chickens to use artificial light during the molt. Pullets can have the additional light (as they don’t molt the first year) but older flocks only *after* they’ve all regrown feathers. I read a study (geared for commercial farmers) that showed that rushing the molt with light had a longterm negative impact.

    • I am relieved to hear that I am not the only one with 15 hens and no eggs! Actually, I have one three-year-old buff who is laying about every other day. But otherwise, piles of feathers everywhere and we are stuck with cereal for breakfast most days.

  6. Patsy Cline, my copper Maran, has thin shelled eggs sometimes, she is a HUGE talker, talks about everything. If I am working around the coop, she stays agitated and tells me non stop.
    Same thing here, other hens have wonderfully thick shells.