Do chickens vomit?

I have just been to give my hens a treat and one of my orpingtons brought back some water and seed, she them with the others started eating the seed, so do chicken vomit? Pol

yes the crop could have been overfull but the water did not spill out of the beak it came out with some force

This is the answers I got off Answers.com 

Chickens might vomit for a number of different reasons. They usually "vomit" water after drinking too much or had been drinking when they were picked up. They might also be sick due to a disease or a bug.

You're welcome Pol!

Is her crop okay?  I had a couple of those chicks in the brooder shed with sour crop, how they got it being inside I don't know, but one of them brought up some liquid when I picked her up.