I am new to ordering poultry to be delivered by mail, so this is news to me that they ship extra chicks for warmth. What do people do with the extra chicks if they don't want that breed or can only have a couple of chickens, total? I did read somewhere that the extra chicks are usually roosters, so even more reason that they might not come to a good end. It seems somehow wrong to me to use a live animal that is most likely not wanted as packing material/heat pack.
In this case you got six chicks. I bought six chicks, and I know how much 'stuff' it takes to raise them and how much time to take care of them properly, so can't imagine ordering waterfowl and getting six chicks to take care (or not) of at the same time.
I probably don't really want to know what happens to them, but can't help wondering.