Does a hen know when an egg is dead?


10 Years
May 18, 2009
Birmingham, AL
I've searched all over the internet and can't find an answer to this question...

Two of my hens have been broody for about 2 weeks now. I'm new to chickens, and this is my first brooding experience - so needless to say I "check on them" a lot
They seem to be trading eggs back and forth and taking turns brooding all the eggs at once...Occasionally they will pick out 2-3 eggs and dispel them from the nest. At first I would put the eggs back underneath them, thinking that they had just forgotten about them, but I noticed that some of the same eggs kept being tossed out. (They could have all been the same, actually, but only a couple of them had distinctive spots that allowed me to be able to tell them apart from the others.) After seeing the same eggs rejected by the hens 3 times, I stopped putting them back under the hens and decided to crack the them open for curiosity's sake. All 3 of the eggs contained chicken embryos in various stages of development. One of the embryos already had the shape of a chicken...

My question though is why did the hens keep throwing out the same eggs? Can they tell when something is wrong with an egg, or can they tell if an egg is from a rival hen? Also, what should I do with these eggs in the future?

Thanks in advance!
Separating broody hens would be a good thing to do. But I have had hens "throw out" bad eggs. Sometimes they would miss one or so but they would try to only hatch the good eggs. As far as it not being documented I would not doubt that. It would depend on the hen if she is getting rid of only the bad eggs knowingly. I would say that any hen would not be able to tell her eggs from another hens but I just have not see it. This happens in other birds, but chickens I don't know. Sometime I think the hen will mistake a good egg for a bad egg (or opposite). But who really knows those eggs that we think are good could actually have a chick with problems if it hatches.
As for what to do with egg like this in the future.....what ever you the hen.....or try to finish incubation yourself if they are still alive.
Last edited:
Hens dont generally "throw out" any eggs. When one hen leaves to feed or drink, the other one is probably trying to steal her eggs. They should never be close enough to do that. The same eggs are probably nearest the front of the nest so they get thrown out when the other hen comes back and they start arguing over whose eggs and nests are whose. If you have the time to watch them while working in the barn it might shed some light. But I would definitely separate them. When eggs are hatching, the hen can tell if the little pips stop and they are all out, she may leave then with the hatched ones, but wont throw out any bad ones, just desert them. You really need to put a barrier between them if you cant move them. They sound like good moms, so it should all work out.
Hens may shove out bad eggs. Not all and occasionally one even explodes under a hen but sometimes they will shove the same bad egg out repeatedly irregardless of where you put it back at. You shouldn't have a bunch of eggs containing formed chicks though. Hens don't lose many chicks that start to form unless something is going on. Either a problem with the eggs like shipping damage, illness, or medication treatments doing damage before incubating or your hens could be causing the death of the chicks while passing the eggs back and forth then shoving the resulting dead eggs out. The veining and new embryo forming during the first week is rather sensitive to being knocked around.
put your hens in a dog crate, separated so they aren't moving the eggs around trying to steal them

You should mark the ones being tossed out before you put them back, to make sure it's the same ones. A pencil mark won't hurt the chick inside, and if you think the egg is bad anyway, use a Sharpie so you can't mistake it. That's what I'd do. You could also candle a good selection of the eggs to see if the ones tossed out are really noticeably behind all the others or somethin like that...
Thanks for all the great advice! I will definitely try to separate the hens. Haha I thought that they were sort of helping each other out by taking turns with the eggs.

Any suggestions or tips on moving the eggs and the hens? Some of the eggs are 2 weeks old now - are they still safe to move? If I move the hens' nests entirely, are they likely to abandon the eggs?

Also, can anyone tell me how easy or difficult it is to build and use your own incubator for the first time? I've been looking at the homemade incubators in the contest, and I would love to try it - but I'm afraid my attempt would end in tragedy.

Thanks again!

New posts New threads Active threads

Top Bottom