I hear clinicians and commentators say, “The horse is thinking, he is licking and chewing.”
Unless the horse is dead, he is always thinking. The horse may not be thinking what we want them to think but they are thinking. The licking and chewing means something else. It is a sign of submission. The horse is accepting leadership.
The horse is at its most vulnerable when it is eating. It has its head down, its vision is limited, its sense of smell is limited, and its hearing is limited. When a horse is submissive it replicates this behaviour. It lowers its head and it licks and chews signifying that it feels submissive and vulnerable.
It is not a big issue but I think it is important to understand correctly what the horse is communicating to you. It may help you when you are playing with your horse.