The natural world contains a vast array of chemical compounds, many of which can profoundly alter the physiological state of any creature that consumes them. This capacity to induce altered states of consciousness is not exclusively a human pursuit. Animals both intentionally seek out and accidentally ingest intoxicating or psychoactive materials found in their environment. Examining these behaviors offers a unique perspective on altered perception across the animal kingdom.
How Psychoactive Compounds Affect Animal Physiology
Psychoactive compounds interfere with the signaling systems within an animal’s central nervous system. These substances often share a similar molecular structure with the body’s natural neurotransmitters, which are the chemical messengers that relay signals between nerve cells. By mimicking or blocking these native compounds, the foreign molecules disrupt normal brain function, leading to changes in mood, perception, and motor control.
Many hallucinogenic or euphoric plant compounds act as agonists, binding to receptors normally meant for neurotransmitters like serotonin or dopamine. An increase in dopamine activity is associated with the brain’s reward pathway, which reinforces the behavior that led to the substance’s consumption. Other toxins may block inhibitory messengers like Gamma-aminobutyric acid (GABA), resulting in overstimulation of the nervous system. The resulting behavioral changes, ranging from stupor to hyperactivity, are physical manifestations of these neurological disruptions.
Animals That Actively Seek Intoxication
Certain animals have developed learned behaviors to repeatedly consume or interact with substances purely for their psychoactive effect. A famous example involves reindeer and the hallucinogenic mushroom Amanita muscaria, or Fly Agaric. Reindeer in the Arctic regions have been observed actively seeking out and eating these fungi, which contain the psychoactive compound muscimol. The consumption leads to erratic movements, twitching, and a state of apparent intoxication, suggesting the animals are deliberately seeking the altered state.
Felines, including domestic cats and large wild cats, frequently seek out the North American plant catnip, Nepeta cataria. The plant releases nepetalactone, a volatile compound that triggers a euphoric or hallucinatory response when inhaled. This behavior, which includes rolling, pawing, and excessive rubbing, is a goal-oriented action where the animal seeks the plant for the temporary sensory experience, not for nutrition.
Another instance of deliberate seeking involves young dolphins gently manipulating pufferfish to elicit a controlled release of a powerful defensive neurotoxin called tetrodotoxin. While this toxin is deadly in large doses, a small, sub-lethal amount appears to induce a trance-like state in the dolphins. The marine mammals have been filmed passing the pufferfish around for up to 30 minutes, after which they enter a period of mesmerized floating, indicating intentional use of a natural intoxicant.
Accidental Consumption of Natural Toxins
Intoxication often occurs as an unavoidable side effect of foraging for food, rather than a deliberate search for a mind-altering experience. This is common when animals consume overripe, fallen fruit that has begun to ferment, producing ethanol (alcohol). Birds, such as cedar waxwings, and mammals, including raccoons and monkeys, can exhibit signs of drunkenness, stumbling or losing coordination after consuming these fermented fruits. The animal seeks the fruit’s sugar content, and the resulting intoxication is purely incidental.
Grazing animals frequently encounter psychoactive substances as they forage through pastures and fields. In Tasmania, wallabies and sheep have been documented accidentally consuming the alkaloid-rich seed pods of legal opium poppies (Papaver somniferum). Ingestion of the opiate alkaloids causes them to stagger and move in circles, sometimes creating noticeable “crop circles” before falling asleep.
Livestock in the American West are susceptible to accidental poisoning from locoweed, which refers to various species of Astragalus and Oxytropis plants. When preferable forage is scarce, cattle and horses consume locoweed, which contains the toxin swainsonine. Chronic ingestion of this toxin causes a degenerative neurological condition called locoism, characterized by an irregular gait, extreme nervousness, and aggressive behavior.