Since time immemorial, humans have amused themselves through intoxication. Whether it was our cavemen ancestors chewing on hallucinogenic plants, medieval villagers unwinding with a cup of mead, or the hippies of the 60’s indulging in psychedelics, it’s safe to say that drug use is one of our oldest pastimes.
However, humans aren’t the only ones who use drugs. There are many cases of drug-use in other animal species.
Cats Using Catnip
One of the most familiar examples of animals using drugs is that of cats and catnip. Many cat owners have witnessed their pets’ enthusiasm when presented with this potent herb, which often produces humorous changes in their behavior.
When exposed to catnip, cats will eat its flowers and rub themselves on the leaves and stems. In a matter of minutes, the cats will begin to show signs of intoxication, including sniffing, rolling, licking, rubbing themselves, stretching, jumping, and sleepiness. Some cats will drool. It is is also thought that cats hallucinate while under the influence of this herb, given that many will start to exhibit hunting behaviors even when no prey is present.1
The chemical that induces these reactions is called nepetalactone. Cats seem to respond to the chemical just as they would to cat pheromones, showing behaviors related to sexual arousal. Both male and female cats respond in kind to catnip, showing a decreased attention to prey (typical of males toward female cats in estrous), and rolling (typical of female cats in estrous).
It’s also interesting to note that the “personality” of individual cats has a strong bearing on how they will respond to catnip: those that are outgoing and friendly will have a more positive response than peers who are withdrawn. Catnip-sensitivity is a genetically inherited trait; only 33% of cats do not respond to nepetalactone.
It’s not only domestic cats that love catnip. Big cats like tigers, leopards, and lynxes have a fondness for it as well. Some wild cat species also seek out other drugs in the wild. For instance, Jaguars have been known to eat ayahuasca, also known as yagé. This plant contains the psychedelic compound DMT, which causes vivid hallucinations and a heightening of senses.
Dolphins Squeezing Puffer Fish
Dolphins have been observed on multiple occasions2 carrying puffer fish in their mouths, squeezing them, and passing them along to other dolphins. It is speculated that the dolphins are trying to get the puffer fish to release a small burst of neurotoxin, which puts them into a trance-like state.
This behavior was recorded in a BBC documentary produced by zoologist Robert Pilley, who commented “This was a case of young dolphins purposefully experimenting with something we know to be intoxicating. After chewing the puffer and gently passing it round, they began acting most peculiarly, hanging around with their noses at the surface as if fascinated by their own reflection. The dolphins were specifically going for the puffers and deliberately handling them with care. Dolphins seem to be experts on how to prepare puffers and how to handle them.”3
Since the toxin released by the puffer fish is deadly in large doses, the dolphins would indeed need to handle the fish delicately in order to avoid lethal poisoning.
Cows Grazing on Locoweed
Cows, as well as other ungulates such as sheep and horses, will sometimes seek out a plant called “locoweed”. This intoxicating plant acts as a tranquilizer, putting animals into a stupor of calmness.4
Many times, animals will stand in place for extended periods after consuming locoweed, seemingly uninterested in socialization or any other activity. Once an animal begins to graze on locoweed, it is very difficult for them to stop. Rather than being an addiction5, persistent grazing on locoweed is thought to simply be a socially-learned behavior6, though this is disputed.
Unfortunately, ingestion of locoweed is highly dangerous, causing a serious disease known as “locoism”. After an animal has grazed on locoweed for 2 weeks or more, it will begin to show signs of toxicity. Symptoms include weight loss to the point of emaciation, reproductive dysfunction, miscarriages, and neurological damage. Animals with locoism develop unstable behavior, and can be dangerous to interact with due to unpredictable aggression, flight responses, and extreme nervousness. Some will also fall into depression.
The toxin of locoweed can be transferred to infant animals through a mother’s milk if the mother is grazing on locoweed, causing irreversible damage. Ranchers and farmers must put in great effort to prevent their livestock from ever grazing on locoweed if they hope to save them from suffering locoism.
Big Horned Sheep Scraping Hallucinogenic Lichen
In the Canadian Rocky Mountains, Big horned sheep will completely deviate from their normally small foraging territory and herds in order to satisfy their addiction to hallucinogenic lichen.
Their lichen of choice grows in areas that are too harsh for other plants, meaning that the sheep must risk climbing narrow paths and steep ledges in order to reach it.
Once they do, the sheep will scrape off the lichen with their front teeth. Many sheep will grind their teeth down to the gums if it’s necessary to get their “fix”. Local humans noted that these sheep often displayed strange behavior in comparison to their un-addicted herd mates.4
Deer Eating Psychedelic Mushrooms
Many types of deer will dine on psychedelic mushrooms, including moose and caribou.
While foraging, the deer will seek out fly agaric (Amanita muscaria) mushrooms frozen beneath winter snow.7 Human observers have stated that after eating the fungi, the deer often display “drunken” behavior, including aimless running, head-twitching, and noise-making.
Caribou that are under the influence of fly agaric will separate themselves from their herd, often at a high cost. Their intoxication leaves them in a vulnerable state which can be taken advantage of by predators, and their unattended calves are put in the same danger.
Ingestion of the mushroom infuses the caribou’s urine with pyschoactive agents, meaning that it too can be consumed for a high. Caribou will fight amongst each other in order to access the urine of a herdmate that has eaten fly agaric. In noticing this, humans realized that they too could benefit from the consumption of intoxicated caribou urine.
In Siberia, Scandinavia, and other regions where caribou herds abound, this became a native custom. After passing through the deer’s system, the psychoactive agents of the fungi are actually more potent, and many of the chemicals that cause undesirable side effects have been filtered out. Whether caribou or human, any being that drinks this urine will experience a more powerful high than the original eater of the mushrooms.
Wallabies on Opium
In 2009, Tasmanian attorney general Laura Giddings reported that wallabies are causing great problems for crop security. “The one interesting bit that I found recently in one of my briefs on the poppy industry was that we have a problem with wallabies entering poppy fields, getting as high as a kite and going around in circles, then they crash. We see crop circles in the poppy industry from wallabies that are high.” she said.
Since opium is addictive, it is not surprising that there are also reports of wallabies returning to the fields time after time to feed.8
Interspecies Affinity for Alcohol
Dr. Robert Dudley proposed what is known as “The Drunken Monkey” hypothesis: that humans have developed an attraction to alcohol because of evolutionary adaptations.9 One of the main food sources of our primate ancestors was over-ripened, fermented fruit. These foods provided a higher caloric content for the primates, meaning that they did not need to spend as much time and energy foraging for other sources of sustenance. Through natural selection, the primates developed a preference for fermented foods. This predisposition was passed on to humans via evolution.
A liking for alcohol is not limited to only humans and our ancestors, it is also found in other primates of today, as well as many other species.
Bees prefer to consume fermented saps and nectars, and will drink 100% ethanol if given the chance. “We can get them to drink pure ethanol, and I know of no organism that drinks pure ethanol – not even a college student.” says researcher Charles Abramson.10
However, drunkeness is not well tolerated in bee societies. Alcohol affects bees much in the same way that it does humans, causing disorientation. Intoxicated bees are more likely to get into accidents while flying, get lost, and fail to share food.11 All of this has an effect on a bee’s ability to contribute to the hive. If a bee is repeatedly intoxicated, its hive-mates will become aggressive toward it, attacking it until its limbs are removed or it is killed.
“In 1990, veterinarians measured alcohol levels in two recently deceased cedar waxwings that had eaten hawthorn fruits, and then tragically fallen from a rooftop. Alcohol concentrations in the livers and crops of these birds were ten to one hundred times higher than those measured in control bird species, suggesting a high level of alcohol ingestion.
Cedar waxwings seem to be at particularly high risk in this regard given their repeated appearance in the popular literature; multiple reports in North America have them flying drunkenly into windows and buildings. Fruit-eating birds in the temperate zone may also be particularly susceptible to inebriation when they consume berries fermenting in the spring thaw. A 2012 report from Cumbria in the United Kingdom similarly reported high levels of alcohol in dead blackbirds and redwings, consistent with lethal intoxication.
Australian lorikeets have similarly been reported to become drunk while feeding on fermented nectar, ultimately becoming unable to fly. In fact, it might be particularly dangerous to drink alcohol while flying.
A series of studies on fruitbats in the Negev desert suggested that, although they can sense alcohol in solution at very low levels, aqueous concentrations above 1% are actually avoided. Nocturnal flights to and from communal roosts are obligatory for these large bats, and any inability to fly would involve substantial risks for them to predators, and indeed for any flying animal that has but limited mobility on the ground.
Behavioral responses to alcohol are thus likely to vary with the animal species in question, and with different aspects of its physiology and natural ecology.”
– Excerpt from The Drunken Monkey: Why We Drink and Abuse Alcohol
Some of the animals that indulge in alcohol become dependent on it, showing signs of addiction. When given the option, chimps will consume enough alcohol on a regular basis to experience withdrawals when access to the alcohol is removed.12
Fruit flies show a preference for solutions containing ethanol, and the higher the ethanol level, the better. Because of this and the fact that they will return to “binge drinking” even after long periods of being denied alcohol, fruit flies are considered a suitable animal model for studying alcoholism.13 It’s worth mentioning that alcohol consumption has an influence on fruit fly sexuality, and vice versa. Fruit flies that are sexually deprived tend to drink more alcohol14, and when they are continuously drunk, male flies will display homosexual behaviors.15
To see monkeys thieving alcoholic beverages from humans and hear about their drinking rates, watch the video below.
More About Animal Drug Use
Despite the diversity of the examples of animal drug use listed above, there are still many more documented cases. To learn more about the ways in which animals seek out recreational intoxication, read Animals and Psychedelics: The Natural World and the Instinct to Alter Consciousness by Giorgio Samorini, and Intoxication: The Universal Drive for Mind-Altering Substances by Robert Siegel.
This article was written by Amanda Pachniewska, founder & editor of AnimalCognition.org
Photo credit: Tomi Tapio K
1 – Arthur O. Tucker, Sharon S. Tucker
Catnip and the Catnip Response
2 – Steiner, Lisa
Rough-toothed dolphin, Steno bredanensis: a new species record for the Azores, with some notes on behaviour
Universidade dos Açores
3 – Dolphins ‘getting high’ on puffer fish, zoologist Rob Pilley says
News Corp Australia Network
4 – Ronald K. Siegel
Intoxication: The Universal Drive for Mind-Altering Substances
5 – M.H. Ralphs, Et al.
Grazing behavior and forage preference of sheep with chronic locoweed toxicosis suggest no addiction.
Journal of Range Management
6 – M.H. Ralphs, Et al.
Social Facilitation Influences Cattle to Graze Locoweed
Journal of Range Management
7 – Giorgio Samorini
Animals and Psychedelics: The Natural World and the Instinct to Alter Consciousness
8 – Stoned Wallabies Make Crop Circles
9 – Dr. Robert Dudley
The Drunken Monkey: Why We Drink and Abuse Alcohol
10 – Emma Yong
11 – T. Andrew Mixson, Charles I. Abramson
The Behavior and Social Communication of Honey Bees (Apis Mellifera Carnica) Poll.) Under the Influence of Alcohol
12 – W.A. Pieper, Et al.
The Chimpanzee as an Animal Model for Investigating Alcoholism
13 – Anita V. Divineni
Preferential Ethanol Consumption in Drosophila Models Features of Addiction
14 – G. Shohat-Ophir, Et al.
Sexual Deprivation Increases Ethanol Intake in Drosophila
15 – Hyun Gwan-Lee, Et al.
Recurring Ethanol Exposure Induces Disinhibited Courtship in Drosophila