Some animals' heads keep moving if you tempt them with food.

Good morning, I was testing the snapshot version of this week and when I wanted to make a pen for cows the moment I tempted them with food to take them with me when running, I saw that they kept their heads moving up and down. I thought it was just the cows but I also tried the sheep and the same thing happened too. I think it will also happen with the rest of the animals. I will detail it more later when I meet pigs and chickens.