Horses (Equus ferus caballus), domesticated by humans for over 5000 years, still maintain many primitive habits of their ancestors to this day. These deeply rooted behavioral patterns in genes not only shape the unique way horses survive, but also profoundly influence modern horse breeding, management, and training methods.

In its natural state, horses are typical social animals with a highly organized social structure. A typical herd of horses typically consists of 5-15 individuals, including one dominant stallion, several mares and their offspring, and sometimes several young stallions. This group structure is not fixed and unchanging, but dynamically adjusts with factors such as season, resource distribution, and individual age. There is a strict hierarchical system within the herd of horses, which is established through complex social interactions, including ear posture (leaning forward to indicate friendliness, sticking back to indicate threat), slight neck biting movements, and physical contact. It is interesting that this level is not entirely determined by physical strength, as some older mares often occupy higher social positions based on experience. Horses strengthen social connections by grooming each other (usually lightly biting each other's neck and back with their teeth), which not only helps clean hard to reach areas but also releases endorphins, bringing a sense of pleasure.

Horses have extremely developed perception systems. Their field of view is close to 350 degrees, with only visual blind spots located directly behind and below. This wide-angle field of view allows them to detect potential threats in a timely manner, but also leads to their instinctive fear of objects that suddenly appear in blind spots. The horse ear can independently rotate 180 degrees, accurately locating the sound source position like a radar. Their sense of smell is several times more sensitive than that of humans, and they can identify individuals, judge food safety, and even perceive human emotional states through odors. In terms of communication, Ma Fa exhibited a rich "language" system: short moans are often used for long-distance communication, low hums indicate warnings, and deep sighs indicate relaxation. The wagging of the tail is not only used to drive away mosquitoes, but fast and powerful movements often indicate irritability or dissatisfaction. It is worth mentioning that horse equipment has a strong mirror neuron system, which can quickly learn the behavior of companions. This is also the reason why old horses are often used to lead new horses when training horses.

As a typical morning and dusk animal, horses are most active in the early morning and dusk. This habit not only avoids the heat of noon, but also effectively avoids the peak activity of predators. In natural environments, horses walk 10-20 kilometers every day in search of food and water sources. If there is a lack of sufficient exercise space in modern animal husbandry, it is easy to develop stereotyped behaviors (such as circling in a stable). The sleep pattern of horses is unique: they only need 2-3 hours of deep sleep per day and can maintain alertness through the "standing sleep" mechanism (relying on the "resting device" of the forelimbs to lock the knee joints). They only enter rapid eye movement sleep in a lateral position when they feel absolutely safe, which is maintained for only 20-30 minutes per day. When observing a herd of horses, it can be observed that they always take turns resting and keep at least one horse on alert.

The digestive system of horses has fully adapted to a coarse fiber diet. As a 'continuous forager', wild horses spend 12-16 hours a day eating and consuming a large amount of low nutrient density grass. This feeding pattern requires continuous secretion of saliva (up to 40 liters per day) to buffer stomach acid, so sudden changes in feeding rhythm in modern feeding can easily cause stomach ulcers. Although the single stomach of a horse is relatively small (only 8-15 liters capacity), its well-developed cecum (up to 30 liters) can break down cellulose through microbial fermentation. It is worth noting that the digestive tract of horses must maintain continuous operation, and not eating for more than 4 hours may cause intestinal obstruction. This physiological characteristic explains why horses are so cautious about unfamiliar food - in the wild, the cost of accidentally consuming toxic plants is fatal. Horses also demonstrate unique skills when drinking water: they can use their lips to form a "straw" that can inhale 10-15 liters of water per minute, but never drink through their nose.

The reproduction of horses exhibits obvious seasonality, with female horses entering estrus during extended spring sunshine. This photoperiod regulation is achieved through melatonin secreted by the pineal gland. Stallions exhibit a unique "Fleeman reaction" during their estrus period - rolling up their lips to better receive the mother's pheromones. Pregnancy lasts for up to 11 months, and mares usually choose to give birth on moonlit nights, which may help foals remember their surroundings faster. The development speed of newborn foals is amazing: they can stand within 30 minutes, start breastfeeding within 1 hour, and run within 24 hours. The mare establishes a connection with the foal through a unique "mother son call", a frequency that is not used for communication between adult horses. In the wild, 2-3 year old young stallions will be driven out of their herds by stallions, forming a "bachelor group" until they are strong enough to challenge the leadership of other herds.

Horses are extremely sensitive to environmental changes, which stems from their evolutionary history as prey. Their stress response system is highly developed, and when faced with threats, their first choice is always to flee (up to 70 kilometers per hour), followed by confrontation. It is interesting that horses have a particularly long-lasting memory of stress, and a negative experience can affect them for months or even years. Modern research has found that the heart rate variability of horses is an important indicator of their psychological state, and well-trained horses can recover their baseline heart rate faster under stress. Horses also have a keen perception of weather changes, and they can detect storms several hours in advance, exhibiting behaviors such as restlessness and frequent defecation. In extremely cold environments, the fur of horses thickens to form an air insulation layer, while the metabolic rate increases by 20% -30% to maintain body temperature.