The question of whether snakes can sense human pregnancy is persistent, often fueled by personal stories. While science has not directly studied this claim, we can examine it by looking at a snake’s biology and the changes a person undergoes during pregnancy to see if a connection is plausible.
How Snakes Perceive Their Environment
Snakes possess a sensory system designed to interpret their surroundings for survival. Their most recognized sense is chemoreception, the ability to detect chemical cues. They accomplish this by flicking their forked tongue to collect chemical particles, which are then delivered to the vomeronasal organ (or Jacobson’s organ) in the roof of the mouth.
This organ analyzes chemical signals, providing detailed information about prey, predators, or potential mates. This process differs from smelling through nostrils, as it directly analyzes non-airborne odors. The forked tongue also provides a directional sense of where a scent originates.
Certain snakes, like pit vipers, pythons, and boas, also possess thermal perception through heat-sensitive pit organs on their faces. These organs detect minute temperature fluctuations, allowing the snake to “see” a thermal image of its surroundings. This ability helps them locate warm-blooded prey, even in complete darkness.
Physiological Changes During Pregnancy
Pregnancy causes significant physiological changes to support the developing fetus. One consistent change is a rise in basal body temperature, which results from a higher metabolic rate as the body works harder.
Hormone levels also alter significantly, with a surge in progesterone. These hormones can subtly change a person’s natural body odor. The chemical compounds in an individual’s scent profile can shift in concentration, creating a chemical signature unique to the state of pregnancy.
Connecting Snake Senses to Pregnancy Changes
A snake’s sense of chemoreception is the most plausible mechanism for detecting these physiological shifts. It is theoretically possible that a snake’s Jacobson’s organ could detect subtle scent changes caused by pregnancy hormones. The snake might not “understand” pregnancy, but it could notice that its owner’s familiar scent has changed.
However, a person’s scent is not static and is influenced by diet, stress, and hygiene products. A snake would have to distinguish hormonal changes from these other variables to identify pregnancy, and no scientific evidence suggests they can. Any perceived behavioral change is likely a reaction to a generally unfamiliar scent, not a recognition of pregnancy.
The ability to detect infrared radiation presents another possible connection. Snakes with pit organs could sense the minor increase in a pregnant person’s body temperature. Like scent, however, a slight temperature increase is not unique to pregnancy and also occurs with fever or after exercise. The snake would simply detect a slightly warmer object, not the underlying cause.
The most probable explanation for a snake’s different behavior relates to behavioral cues. A pregnant individual may move more cautiously, have a different posture, or experience shifts in stress levels. Snakes are sensitive to vibrations and handling changes, so they are likely reacting to these alterations in their owner’s behavior.
Explaining Anecdotal Evidence and Safety Considerations
Belief in this idea persists due to anecdotal stories and confirmation bias. An owner who believes the myth may interpret any ambiguous behavior from their pet, like being more cuddly or defensive, as proof. This leads to attributing complex reasoning to the snake’s behavior that isn’t supported by its biology.
The snake is likely reacting to a change in handling, but the owner connects it to the pregnancy. This reinforces the myth, which is then shared through community stories.
Regardless of a snake’s abilities, safety practices are important for expectant parents who own reptiles. The primary health concern is the risk of salmonella, a bacterium commonly carried by reptiles. A salmonella infection can be more serious for a pregnant person and poses a risk to the fetus.
Pregnant individuals should wash their hands thoroughly with soap and water after handling any reptile or its enclosure. They should also consider having another person take over cleaning duties to minimize exposure.