I assume nothing about the souls of humans or chickens.
The existence is a soul has never been proven nor disproved. We find it convenient to assume that chickens have no souls, primarily because that chickens, when fried, are delicious. Naturally, we do not wish to feel guilt about eating chickens or other animals. Pigs are especially smart, but no matter, bacon is especially delicious.
It would seem that there is as much reason to assume that some animals have souls. We share something like 97% of our DNA with chimpanzees, after all.
What we do know is that if the soul does exist after death, wherever it goes, it does not come back and tell us about it. Jesus came back, we hear, but he really did not say much about life in Heaven. We seem to have gotten the idea that there will be a lot of singing in the Choir Celestial, and also that this singing and listening to others sing, will be particularly pleasant. Having sung in choirs, I have noticed that even the best singing gig gets pretty tedious after an hour or so, even if you do not have to pee.
God's guidance, if there is any, is to be found,not in the Bible or Koran, but in our DNA and our manner of thinking, or so it seems to me.