An incredible survival instinct. Understanding horse behaviour

Many behaviours that people at the yard call “stupidity”, “stubbornness” or “hysteria” are a well-functioning survival programme. A horse doesn't spook to annoy you, and it doesn't whinny after other horses on a whim.

Below we explain where these behaviours come from. At the end you'll find a table that links what you see to its cause.

A horse thinks like a prey animal

Horses have lived with people for about 4,000 years. An analysis of 273 ancient horse genomes showed that today's domestic horses originate from the steppes of the lower Volga and Don, from where they spread rapidly across Eurasia from around 2000 BC[1]. The genomes of these horses show strong selection in two genes linked to locomotion and behaviour[1].

Domestication changed horses, but it did not erase their heritage as prey animals. In a study from the Czech Republic, semi-feral Exmoor ponies were played wolf howls, the roaring of red deer stags during the rut, and plain noise. The horses' reactions to both animal sounds differed clearly from their reaction to the noise. The authors concluded that horses can tell these sounds apart and probably still have an innate memory of danger[2].

Senses tuned for early warning

A horse's senses evolved to detect a predator as early as possible and flee[3]. Eyes on the sides of the head give an almost panoramic view: the visual field of one eye extends up to 228 degrees. The blind spot behind the horse is small[3], but big enough for an approach from behind to take the horse by surprise.

Binocular vision in front of the horse, on the other hand, is narrow, about 55–65 degrees, compared with about 120 in humans. Only in this field does a horse see in three dimensions, that is, judge depth from the images of both eyes[3]. That is why a horse that wants to take a close look at something often turns to face it.

Horses see better than humans in low light, which researchers link to predators that hunt at night[3]. They hear high-pitched sounds that humans can no longer hear, and they have a very good sense of smell[3]. The smell of a wolf or lion alone did not frighten horses, but it did make them more vigilant[4].

An interesting research finding: horses reacted more strongly to a frightening stimulus shown on their left side[3]. So it is worth getting a horse used to new things from both sides.

Flee first, ask questions later

In a situation that triggers fear, a horse usually flees first. This reaction can be dangerous both for the horse and for people[5]. For a prey animal, it is a sensible strategy: an unnecessary escape costs less than one that comes too late.

Flight is also contagious. When one horse spooks, the reaction easily spreads to the others. This is known as social facilitation: the behaviour of one animal triggers the same behaviour in others[6].

Horses are also afraid of things that seem harmless to people. In a study by a team from the University of Life Sciences in Lublin, a cow caused the highest heart rate in horses led in hand. The horses avoided it at least as much as an unfamiliar moving object[7].

The strength of the reaction depends on temperament: fearfulness proved to be a trait that is stable over time and consistent across situations[8]. Punishing fear-based behaviour has well-documented side effects, including fear that a horse can remember after a single incident[9].

When it can't flee: tension and resistance

Flight is not always possible. A horse that is tied up, standing in stocks or pinned against the stable wall has to cope in a different way: it freezes, stiffens, pushes into the person or braces against pressure. Being restrained is stressful in itself. Horses in stocks with no other horse nearby had a higher heart rate, faster breathing and more facial signs of stress[10].

Stillness does not always mean calm. A review of research on equine senses describes horses restrained with a twitch that, after a while, can suddenly and violently panic. The authors suggest this is an ancient response to a predator: the animal goes still when held and breaks free when the grip loosens[3].

What people at the yard call “resistance”, “evading the aids” or “disobedience”, researchers propose calling conflict behaviour. In their view, such labels blame the horse from the outset and can mask pain. Conflict behaviour arises from the horse's conflicting needs. It can be barely noticeable or very obvious, a one-off or repeated when the conflict goes on for a long time[11].

A horse learns from the moment the pressure goes away: the release of pressure tells it that it has done what was asked[9]. In a study of trot-to-walk transitions, riders who released the reins before the horse began to slow down got a slower response[12]. So precise timing matters.

The herd is a security system

For a horse, the herd is above all protection. A 2025 review of research on horses' anti-predator behaviour indicates that the most effective defences are group cohesion, joint synchronised flight, gathering the foals together, and kicking and chasing off the attacker. The risk of wolf attacks is influenced by factors such as group size and whether the group is stable[13].

This is where synchrony comes from: horses eat together, rest together and move together[13]. Group dynamics also affect situations involving people, for example when you take one horse out of the paddock and the rest stay behind[14].

The herd also has a calming effect. Young horses that looked at a frightening object in the company of a calm horse already used to it were less afraid and had a lower heart rate. The effect persisted when they later saw the object on their own[5]. A single calm adult horse in a group of youngsters reduced their reactions to a frightening stimulus[15].

Company does not remove every fear. When an umbrella was suddenly opened, a second horse did not reduce the reaction, but heart rate returned to normal faster. It made no difference whether the companion was familiar[16].

Even the mere sight of another horse is calming. Horses standing in stocks had a lower heart rate, slower breathing and fewer facial signs of stress when a familiar, calm horse stood 3 metres away, without physical contact[10].

Hierarchy and friendships

There is a hierarchy in the herd, but it works differently from what is often said. Dominance in horses mainly concerns priority access to limited resources such as hay or water. Predictable relationships can limit the number of conflicts. The higher levels of aggression in domestic herds than in wild horses are often the result of management conditions[14].

Nor is there a single “lead mare”. In wild horses, any member of the group can initiate the movement of the whole group, although the group follows higher-ranking horses more often[18]. Should a person “become the herd leader”? A review of research shows that this is still debated: it is not known whether a horse's role in the herd matters for how it responds to people[14].

Horses do, however, form bonds with particular horses, and researchers link these bonds to group cohesion and defence[13]. Mutual grooming also has a physiological side: scratching a horse's favourite spot at the base of the neck lowers its heart rate[19].

Body language in the herd

In the herd, the body conveys the most information. Some signals can be seen from a distance: ears laid back, a bite threat, a raised and tensed hind leg before a kick[20]. Many signals, however, are subtle and easy to miss. Research describes several such indicators:

• Wrinkles above the eye. Their angle increased when horses competed for food and decreased during grooming[21].
• Blinking. After separation from companions, when feeding was withheld and after a sudden fright, horses blinked less. When feeding was withheld, their eyelids also twitched more often[22].
• Soft snorting. It was associated with pleasant situations, such as grazing on pasture, and was heard more often in horses with fewer signs of chronic stress[23].
• Vacuum chewing. After a sudden fright, horses more often chewed with an empty mouth and made a sound through the nose that the authors call a snort. Researchers link the snort to the body returning to balance after stress[24].
• Shifting weight from leg to leg. Frequent weight shifting is one of the behaviours described as signs of discomfort[25].

A single signal says little. What tells you the most is several signals at once, compared with how that particular horse usually behaves.

A horse hides pain

For a prey animal, showing weakness is risky. Researchers write that horses have developed a tendency to hide discomfort in the presence of potential predators, including people. In a study of 20 horses after orthopaedic surgery, behaviours indicating discomfort decreased by an average of 77% during a carer's visit, and in 30% of horses they disappeared completely for that time[26].

That is why pain is easy to miss. Among 506 sports horses in normal work, lameness or abnormal movement was found in 45.7%, and the authors stress that many cases of lameness go unnoticed. A saddle that constantly slips to one side can be a sign of hindlimb lameness[27]. In riding schools, carers reported back pain in 12% of horses, while palpation or measurement of back muscle activity revealed problems in almost 50%[28].

Chronic pain can show in small details. Horses with more severe back problems took less interest in what was going on around them[29]. Acute pain changes the face: the position of the ears, the look in the eye, the nostrils and the tension of the lips[30].

Hiding discomfort works even when the observer stands at a distance: in a study cited by the authors, some pain behaviours were visible only on video[26]. So a video recorded while the horse is alone will tell you the most.

Sleeping in shifts

A horse's sleep is also governed by safety. In total, a horse sleeps on average just under 4 hours a day, in many short bouts. Researchers see this split sleep as an adaptation that allows the horse to stay vigilant[31].

A horse can doze standing up, but it has to lie down for REM sleep[31, 32]. REM sleep takes up about 40 minutes a day on average[31]. In a herd, horses often lie down in turns: some lie down while others stand and keep watch[31].

A horse alone in a stable loses this shared watch. In a new place it is also more vigilant and needs time to settle in[31]. A study of young horses fitted with motion sensors suggested that a day in an open paddock with another horse increases lying time, including at night. However, there were only ten horses, and the differences were not statistically significant[32].

The latest study, from 2026, in which sleep was measured with a non-invasive EEG mask, confirmed that housing and the horse's age affect sleep patterns. Younger horses had more REM sleep and spent longer lying down[33].

Loneliness is stressful for a horse

If the herd provides safety, being alone is stressful for a horse. After being moved to individual stables, horses showed changes in their blood picture typical of stress, a short-term rise in cortisol and, after a week, behavioural disturbances. A change in group composition had no such effect[34].

Horses don't “copy” stereotypies such as crib-biting or weaving from their neighbours. A review of research found no strong evidence that horses learn by imitation. Isolating a horse with a stereotypy “so the others don't pick it up”, on the other hand, can harm its wellbeing[6].

Even brief but daily contact helps. Horses from individual stables that spent an hour a day with another horse for 4 months had fewer stereotypies, behaved negatively towards people less often and were less vigilant during grooming[36].

Group living has its costs too. Two-year-old stallions kept in a group had superficial skin abrasions more often. On the other hand, only in the group did the stallions groom each other, and the authors considered both housing systems acceptable[37]. Owners' fears of serious injuries in groups have not so far been confirmed by research[14].

What you see and where it comes from

The table below links everyday behaviours with the instinct behind them.

What this means for you

1. Announce yourselfSpeak before you approach, and come in from the side, within the horse's field of view. An approach from behind easily startles it[3].
2. Introduce things graduallyIn a study of three habituation methods, gradually increasing the stimulus worked best: horses fled less often and needed fewer sessions. Heart rate was sometimes raised even when the horse already looked calm[38].
3. Use a calm companionA young horse learns to stay calm more easily alongside a horse that isn't afraid of the new thing[5, 15].
4. Don't leave the horse on its ownContact with other horses is a need, not an extra[34]. If the horse has to be kept apart, make sure there is a neighbour within sight and daily time with another horse[10, 36].
5. Provide conditions for sleepA horse needs a place where it feels safe enough to lie down. After a move, give it time to settle in[31].
6. Ask lightly, release in timeRelease the pressure the moment the horse begins to yield[9]. Releasing before the horse had responded slowed its response[12]. When a horse pushes against you or stiffens, reduce the pressure instead of increasing it. Don't punish fear: punishment can give the horse yet another reason to be afraid[9].
7. Watch when the horse doesn't know itHorses hide pain around people[26]. Now and then, film your horse from a distance, in the stable or in the paddock, and compare it with what you see every day. Once a week, slowly run your hand over the neck, back and legs, and remember where the horse tenses up or moves away.

Frequently asked questions

Scientific sources

We checked every publication in the Crossref and PubMed databases. The numbers in the text link to the list, and the DOI links lead to the original articles.

1. Librado P, Khan N, Fages A, Kusliy MA, Suchan T, Tonasso-Calvière L et al. The origins and spread of domestic horses from the Western Eurasian steppes. Nature. 2021;598(7882):634-640. doi.org/10.1038/s41586-021-04018-9
2. Bercy A, Ceacero F, Komárková M. Antipredator behaviour in semi-feral horses: innate response and the influence of external factors. Animal Cognition. 2025;28(1):8. doi.org/10.1007/s10071-025-01933-6
3. Rørvang MV, Nielsen BL, McLean AN. Sensory Abilities of Horses and Their Importance for Equitation Science. Frontiers in Veterinary Science. 2020;7:633. doi.org/10.3389/fvets.2020.00633
4. Christensen JW, Rundgren M. Predator odour per se does not frighten domestic horses. Applied Animal Behaviour Science. 2008;112(1-2):136-145. doi.org/10.1016/j.applanim.2007.08.003
5. Christensen JW, Malmkvist J, Nielsen BL, Keeling LJ. Effects of a calm companion on fear reactions in naive test horses. Equine Veterinary Journal. 2008;40(1):46-50. doi.org/10.2746/042516408x245171
6. Rørvang MV, Christensen JW, Ladewig J, McLean A. Social Learning in Horses - Fact or Fiction? Frontiers in Veterinary Science. 2018;5:212. doi.org/10.3389/fvets.2018.00212
7. Wiśniewska A, Janczarek I, Wilk I, Tkaczyk E, Mierzicka M, Stanley C et al. Heterospecific Fear and Avoidance Behaviour in Domestic Horses (Equus caballus). Animals. 2021;11(11):3081. doi.org/10.3390/ani11113081
8. Lansade L, Bouissou MF, Erhard HW. Fearfulness in horses: A temperament trait stable across time and situations. Applied Animal Behaviour Science. 2008;115(3-4):182-200. doi.org/10.1016/j.applanim.2008.06.011
9. McLean AN, Christensen JW. The application of learning theory in horse training. Applied Animal Behaviour Science. 2017;190:18-27. doi.org/10.1016/j.applanim.2017.02.020
10. Bini de Lima AC, Sebastião da Fé VC, Palermo Hernandes MS, Pfeifer de Cristo EC, dos Santos Fagundes Euzébio AG, e Silva Sousa MV et al. Social enrichment mitigates facial expressions and physiological indicators of short-term stress in horses. PLOS One. 2026;21(4):e0347571. doi.org/10.1371/journal.pone.0347571
11. O’Connell E, Dyson S, McLean A, McGreevy P. No More Evasion: Redefining Conflict Behaviour in Human–Horse Interactions. Animals. 2025;15(3):399. doi.org/10.3390/ani15030399
12. Eisersiö M, Egenvall A, Yngvesson J, Hernlund E, Byström A. What is reinforced? The timing of the release of rein tension and the horse’s response latency for trot to walk transitions. Applied Animal Behaviour Science. 2025;285:106590. doi.org/10.1016/j.applanim.2025.106590
13. Voigtländer-Schnabel S, Górecka-Bruzda A, von Borstel UK. Help horses help themselves – A literature review on social relationships in the context of anti-predator behaviour. Applied Animal Behaviour Science. 2025;293:106845. doi.org/10.1016/j.applanim.2025.106845
14. Hartmann E, Christensen JW, McGreevy PD. Dominance and Leadership: Useful Concepts in Human–Horse Interactions? Journal of Equine Veterinary Science. 2017;52:1-9. doi.org/10.1016/j.jevs.2017.01.015
15. Rørvang MV, Christensen JW. Attenuation of fear through social transmission in groups of same and differently aged horses. Applied Animal Behaviour Science. 2018;209:41-46. doi.org/10.1016/j.applanim.2018.10.003
16. Ricci-Bonot C, Romero T, Nicol C, Mills D. Social buffering in horses is influenced by context but not by the familiarity and habituation of a companion. Scientific Reports. 2021;11(1):8862. doi.org/10.1038/s41598-021-88319-z
17. Lundblad J, Rashid M, Rhodin M, Haubro Andersen P. Effect of transportation and social isolation on facial expressions of healthy horses. PLOS ONE. 2021;16(6):e0241532. doi.org/10.1371/journal.pone.0241532
18. Krueger K, Flauger B, Farmer K, Hemelrijk C. Movement initiation in groups of feral horses. Behavioural Processes. 2014;103:91-101. doi.org/10.1016/j.beproc.2013.10.007
19. Feh C, de Mazières J. Grooming at a preferred site reduces heart rate in horses. Animal Behaviour. 1993;46(6):1191-1194. doi.org/10.1006/anbe.1993.1309
20. McDonnell SM, Haviland JCS. Agonistic ethogram of the equid bachelor band. Applied Animal Behaviour Science. 1995;43(3):147-188. doi.org/10.1016/0168-1591(94)00550-x
21. Hintze S, Smith S, Patt A, Bachmann I, Würbel H. Are Eyes a Mirror of the Soul? What Eye Wrinkles Reveal about a Horse’s Emotional State. PLOS ONE. 2016;11(10):e0164017. doi.org/10.1371/journal.pone.0164017
22. Merkies K, Ready C, Farkas L, Hodder A. Eye Blink Rates and Eyelid Twitches as a Non-Invasive Measure of Stress in the Domestic Horse. Animals. 2019;9(8):562. doi.org/10.3390/ani9080562
23. Stomp M, Leroux M, Cellier M, Henry S, Lemasson A, Hausberger M. An unexpected acoustic indicator of positive emotions in horses. PLOS ONE. 2018;13(7):e0197898. doi.org/10.1371/journal.pone.0197898
24. Scopa C, Palagi E, Sighieri C, Baragli P. Physiological outcomes of calming behaviors support the resilience hypothesis in horses. Scientific Reports. 2018;8(1):17501. doi.org/10.1038/s41598-018-35561-7
25. Torcivia C, McDonnell S. Equine Discomfort Ethogram. Animals. 2021;11(2):580. doi.org/10.3390/ani11020580
26. Torcivia C, McDonnell S. In-Person Caretaker Visits Disrupt Ongoing Discomfort Behavior in Hospitalized Equine Orthopedic Surgical Patients. Animals. 2020;10(2):210. doi.org/10.3390/ani10020210
27. Greve L, Dyson SJ. The interrelationship of lameness, saddle slip and back shape in the general sports horse population. Equine Veterinary Journal. 2014;46(6):687-694. doi.org/10.1111/evj.12222
28. Lesimple C, Fureix C, Biquand V, Hausberger M. Comparison of clinical examinations of back disorders and humans’ evaluation of back pain in riding school horses. BMC Veterinary Research. 2013;9(1):209. doi.org/10.1186/1746-6148-9-209
29. Rochais C, Fureix C, Lesimple C, Hausberger M. Lower attention to daily environment: a novel cue for detecting chronic horses’ back pain? Scientific Reports. 2016;6(1):20117. doi.org/10.1038/srep20117
30. Gleerup KB, Forkman B, Lindegaard C, Andersen PH. An equine pain face. Veterinary Anaesthesia and Analgesia. 2015;42(1):103-114. doi.org/10.1111/vaa.12212
31. Greening L, McBride S. A Review of Equine Sleep: Implications for Equine Welfare. Frontiers in Veterinary Science. 2022;9:916737. doi.org/10.3389/fvets.2022.916737
32. Helmerich P, Bachmann I, Gygax L. Comparing lying behaviour of young riding horses on days in an individual indoor box, on an outdoor paddock alone, or in pairs and in the following night. Equine Veterinary Journal. 2024;57(1):277-281. doi.org/10.1111/evj.14041
33. Zimmer L, Schramel JP, Lyrakis M, Trachsel DS, Auer U, Leschnik M et al. Sleep architecture and lying behavior in horses across age groups and two housing systems: an overnight non-invasive EEG study. Frontiers in Veterinary Science. 2026;13:1898580. doi.org/10.3389/fvets.2026.1898580
34. Schmucker S, Preisler V, Marr I, Krüger K, Stefanski V. Single housing but not changes in group composition causes stress-related immunomodulations in horses. PLOS ONE. 2022;17(8):e0272445. doi.org/10.1371/journal.pone.0272445
35. Visser EK, Ellis AD, Van Reenen CG. The effect of two different housing conditions on the welfare of young horses stabled for the first time. Applied Animal Behaviour Science. 2008;114(3-4):521-533. doi.org/10.1016/j.applanim.2008.03.003
36. Flamand A, Robinet L, Raskin A, Braconnier M, Bouhamidi A, Derolez G et al. The social dimension of equine welfare: social contact positively affects the emotional state of stalled horses. Animal Behaviour. 2025;221:123055. doi.org/10.1016/j.anbehav.2024.123055
37. Kroschel L, Pilger F, Aurich J, Nagel C, Aurich C. Group housing increases alertness and social interaction compared to traditional single stabling in two-year-old sport horse stallions during pretraining. Animal. 2025;19(8):101584. doi.org/10.1016/j.animal.2025.101584
38. Christensen JW, Rundgren M, Olsson K. Training methods for horses: habituation to a frightening stimulus. Equine Veterinary Journal. 2006;38(5):439-443. doi.org/10.2746/042516406778400574

Published 7 October 2026. This article is for educational purposes and does not replace an examination by a vet.