Chickens will stop eating when full.
Chickens know when they are full and will eat until they are full and once the chickens are satisfied instead of just being truly full, the chickens will stop eating.
Chickens also self regulate to an extent, but chickens can still overeat and become obese f they are many treats or the wrong diet as a chickens body can fill up on "junk food".
When chickens have a nutritionally complete diet of food that is in constant supply, such as balanced layer feed, the chickens will naturally stop eating when they've had enough to sustain their body and meet their needs.
Chickens will also act like they are starving for treats and scraps, even when the chickens main source of food is plentiful.
Although chickens will also regulate their consumption of their main feed based on how many treats they have.
So in this case, chickens are unlikely to overeat on the balanced feed itself if the treats are limited to 10 percent of the chickens diet.
Overeating in chickens can also become a problem if the chickens diet is not balanced, with too much junk food for an excessive amount of treats, which can lead to health issues in chickens like obesity.
For broiler chickens, a different situation applies, as broiler chickens are bred for rapid growth and can also eat themselves to death if they are not managed carefully.
Providing your chickens with a constant supply of food is very important for the health and egg production of the chickens.
And sometimes people use 2 chicken feeders to ensure less dominant chickens get their share of the chicken food.
Chickens do self regulate and will stop eating once they have had enough food to eat and are satisfied.
Although chickens are not like some other animals, like dogs and cats, which might overeat to the point of becoming fat if they are given an unlimited access to their food.