US chicken companies pioneered restricting sleep to keep birds eating around the clock.
A new study (Li et al., 2026) recommends giving chickens just 2 hours of darkness nightly to maximize the time they spend eating. The study and photo are Chinese.
We know chickens have far better hapiness with 7–8 hours of darkness to sleep.
But they eat more when they are sleep restricted.
Signs of stress, and behaviors that indicate a normative state.
Chickens, when calm and with their flock, make all kinds of sounds and exhibit behaviors like “cuddling”, and even the rare mutual preening. While it’s impossible to point to anything like that and be 100% certain you’ve identified the internal emotional state of an animal, it’s one of those duck things, only chickens. If it looks like a happy chicken, and trills like a happy chicken, might as well say it’s a happy chicken.
If chickens don’t get good rest, you’ll notice all the usual bird stress behaviors appearing. Feather plucking, grumpiness, pecking, angry zipper noises, etc.
So, again, it’s foolhardy to apply human states of mind to anything that can’t speak our language. But some things can be observed and extrapolated to at least be similar.
Side note: the sound a happy chicken makes when cuddling you will either melt your heart, or prove you’re an emotionless wreck. I have wept at that sound
I once had a chicken that would purr like a cat
It’s such a lovely sound :)
Mine only breaks it out when she’s particularly lovey dovey with me. And, obviously, I melt into a puddle when she does lol
Chicken owner here: you can indeed absolutely tell what a chicken is feeling because they have a wide range emotions they will loudly tell you all about.
All my birds are like this. They’re very expressive.
I know what the law says in a lot of places (law != morality), that animals are “property,” but I don’t own my companion animals. They co-exist with me.
Very, very loudly lol.