Is it normal for chicks to lay on their backs?

Chickens cannot breathe easily when on their backs and can aspirate stomach contents (vomit). I do put them on their backs to dust them with poultry dust (someone told me that they had a chicken vomit when they did that).

Holding baby chicks that way is probably ok for a cute cuddle here and there but I'd not try to hold them like that routinely.

Just to cover all bases- vit e deficiency:
http://www.thepoultrysite.com/publications/6/diseases-of-poultry/218/vitamin-e-deficiency

(I am assuming they were just being held and don't have a problem...just thought I'd include the link just in case you needed it.)

 

I agree, it's not a natural position at all. Probably okay for a little bit, but they'll probably start to resist it as they age.

 

LOL, that is cute. We made sure we turned our rooster onto his back as often as we could and never had a problem with him.

People have carried chickens by their feet for a long time and no one ever says it is bad. I wouldn't worry about it. Have fun with your chickens.

 

Not long ago, your chicks were inside their egg shells and were turned every which way for a month, so I doubt being upside down now is going to do them any harm.

You're on the right track handling them a lot. Chicks like yours who are cuddled and loved grow to be tame chickens that are delightfully easy to handle.