Cube mk2 and WIR

[herecomethegirls]

One of our hens has laid an egg (full sized) INSIDE an egg (mutant sized!) is this even possible?! I have never heard of such a thing! It’s the most bizarre thing I have seen in a long time! The giant egg’s shell was fairly soft and the regular egg was inside, surround by egg white! 

[Beantree]

We had an egg inside an egg many years ago. I think it was a Blackrock egg and it was pretty simple being a very small egg (with a yolk) inside an extra large egg (with its own yolk). Didn't think much of it at the time because we were very new to chickens and had no idea what was 'normal' or 'abnormal'. So no photo unfortunately.

You wouldn't think it was possible because the internal egg would have to go back up to the top of the oviduct to then pass back down and be re-enveloped and how on earth could it do that?

[Cat tails]

I think the ‘small’ egg might just not be passed and the next one arrives to be enveloped by shell.

But if you have a search on YouTube, you’ll find more examples.

[herecomethegirls]

It’s happened again! Two days after the first! This isn’t a tiny egg inside a normal egg; it’s a normal egg inside a dinosaur egg!!!! 

[Alison W]

Found this which explains how it happens but not why so no help on preventing it happening again. Hopefully it’s just a glitch & your girl doesn’t have to deal with this again. Making me wince just thinking about it!
 

https://backyardpoultry.iamcountryside.com/eggs-meat/how-a-chicken-lays-an-egg-inside-of-an-egg/

[Daphne]

Very interesting indeed, thanks both for posting in the first place and for the explanation; however, I sincerely hope this doesn't happen any more for your poor girl's sake!