If you use ether make sure you leave them in at least 15-20 minutes. This is a sad story but true. I learned a valuable lesson it's a sensitive subject to me now.
I had a baby chick that couldn't stand at all, couldn't eat or drink and was almost two days old. I put that chick in a closed container with a rag with plenty of ether on it for almost ten minutes,. It died quickly and peacefully, I then took it's dead body out wrapped it in a paper towel and put it in the trash can that was about to be taken out with the shells from hatching.
About 25 minutes later I get the can to take out and hear chirping, the chick came to life, I felt horrible and got all teared up, wanted to save it but I know ether damages eyes and lungs, and I had to get DH to take it outside and finish the job. I felt so bad, I feel like I did it more harm than good, DH said I should have listened to silkiechicken and cut it's head off with a pair of scissors. I just couldn't do it because I'd been trying to save it's life for two days.
That's why I cannot use the bator again for a while because it seemed cruel to me.