How do I find out which one?

[paulandashia]

Brought home 5 new hens.
I had an egg in the nestbox to show them where to lay, and it vanished. Shell and all.

I think it was partly my fault, because I don't think I put enough straw in the boxes, so it probably broke (just fixed that).
But I need to find out which one of the hens ate it.
I know it's late to do so now, but in case it happens in the future, how can I find out which one did it?

 

[Souperchicken]

I had eggs disappearing and decided to put an egg in the pen with the chickens and watch and see who went for it. It wasn't in there for more than about 10 minutes when the rooster started to try and peck it open. He is gone and I haven't had a problem since.

Oh yeah, I wanted to add, some days I would go out to the coop and see several hens with egg on there faces, very incriminating, yet they weren't they ones actually pecking the egg open, they we just enjoying the treat once it was open.