Horses clack their teeth and jaws together as a form of communication, most commonly to signal submission. It’s one of the more distinctive and puzzling things horses do, and the meaning changes depending on the horse’s age, body language, and situation.
What Clacking Looks Like
When a horse clacks, it opens its mouth, draws the corners of its lips back, and makes a rapid chomping or snapping motion with its jaw. The movement produces an audible clicking or clacking sound as the teeth come together repeatedly. It can look almost comical, like the horse is chewing on air or mouthing an invisible piece of food. Some people describe it as “snapping,” “champing,” or teeth clicking. The motion is distinct from chewing, yawning, or cribbing, and once you’ve seen it, it’s easy to recognize.
Foals Use It to Say “Don’t Hurt Me”
The most common and well-understood reason for clacking is submission. Very young foals do it instinctively when they encounter older horses. The movement is essentially an announcement: “I’m a baby, don’t hurt me.” Because foals are always at the bottom of the herd’s social hierarchy, they clack frequently around any horse that outranks them, which is every horse they meet.
This behavior serves a real protective function. Horses in a herd establish a pecking order, and larger, dominant horses can be aggressive toward animals that challenge them or get in their way. A foal clacking its teeth is preemptively signaling that it’s not a threat and isn’t looking for trouble. It’s the equine equivalent of putting your hands up and saying “I come in peace.”
Most foals gradually stop clacking as they mature and find their place in the herd, typically by the time they’re a year or two old. The behavior fades as the young horse gains confidence and no longer needs to broadcast its low status so overtly.
Why Some Adult Horses Still Clack
While clacking is primarily a juvenile behavior, some adult horses never fully outgrow it. These tend to be naturally submissive horses that remain at the bottom of the pecking order. They may clack when introduced to new horses, when a dominant herd member approaches, or even when interacting with humans they perceive as authority figures. An adult horse that clacks at you is generally communicating deference, not aggression.
But submission isn’t the only explanation in adults. Context matters a lot. Some horses clack their teeth out of excitement. Certain working horses, particularly those trained for tasks like cutting cattle, will clack or chatter their teeth when they anticipate doing something they enjoy. One common example is a cutting horse that starts clicking its teeth the moment it sees cows, almost vibrating with eagerness to get to work.
Clacking as a Warning
In some situations, the sound means the opposite of submission. A horse that clacks or snaps its teeth while pinning its ears back and wrinkling its nostrils is telling you (or another horse) to back off. This is a space-guarding behavior, a step below an actual bite. The body language makes the difference obvious: a submissive clacker looks soft and deferent, while an aggressive one looks tense and hostile. If the ears are flat and the expression is hard, the horse is warning you to stay out of its space.
Clacking From Stress or Boredom
Horses that spend long hours confined in stalls sometimes develop repetitive oral behaviors as coping mechanisms. Teeth clicking, grinding, lip flapping, and tongue playing can all develop in horses that don’t have enough stimulation or turnout time. These aren’t communicative gestures aimed at another animal. They’re self-soothing habits, similar to other stereotypic behaviors like cribbing or weaving. A horse that clicks or grinds its teeth while standing alone in a stall is likely bored or stressed rather than trying to send a social signal.
How to Read the Situation
The key to understanding why a particular horse is clacking is reading the rest of its body. A young horse or a naturally timid adult doing the classic open-mouthed chomping motion with relaxed ears and soft eyes is being submissive. A horse that clacks while its whole body is tense and forward-focused is excited. A horse snapping its teeth with ears pinned is threatening. And a horse clicking or grinding in isolation is likely coping with confinement.
If clacking appears suddenly in a horse that hasn’t done it before, especially during riding or tacking up, it’s worth considering whether pain or discomfort could be the cause. Dental problems, ill-fitting tack, or mouth injuries can all produce unusual jaw movements. Persistent teeth grinding or chattering that doesn’t fit any obvious behavioral context may have a physical origin rather than a social one.
Clacking and the Connection to Licking and Chewing
Trainers often note that clacking is closely related to the licking and chewing behavior horses display when they mentally “give in” during training. Both are expressions of yielding or deference. When a horse under pressure from a trainer suddenly drops its head and starts licking and chewing, it’s signaling acceptance of the trainer’s authority. Foal clacking operates on the same principle, just in a more exaggerated, full-mouth version. As horses mature, the dramatic jaw snapping tends to soften into the subtler licking and chewing that experienced horse people watch for as a sign of mental release during groundwork and training sessions.