1. Bohemian waxwing birds get so drunk they have to go to rehab. Paul Reeves/Paul Reeves Photography It's not just humans that indulge during the holiday season. Bohemian waxwing birds, native to the northern parts of North America and Eurasia, love to feast on berries from rowan trees, which ferment when the weather gets cooler, making alcohol.Most birds just get a little buzzed. But others don't know when to stop. Some are even "drunk flyers," which can unfortunately mean fatal crashes with buildings – according to National Geographic, two such collisions were recorded this year.This fall, several birds became so intoxicated that they had to be admitted to the animal healthcare unit in Yukon, Canada to sober up. Those that weren't able to recover, however, had to go to...yes...rehab, at the Yukon Wildlife Preserve. 2. Bats can handle their alcohol. sibadanpics/sibadanpics Just like birds, bats get drunk off fermented fruit. But unlike Bohemian waxwings, bats in Central and South America are able to handle their alcohol. According to a 2009 study in Belize published by PLOS One, the highest blood alcohol content (BAC) that was tested in the bats was 0.3%. To put this in perspective, it's illegal to drive in the United States with a BAC of more than .08%.In the study, the bats were able to successfully fly through obstacle courses, using echolocation. But, this is only true for Central/South American bats. In a study published in the Journal of Experimental Biology, Egyptian fruit bats had higher cases of collisions than their American counterparts. Biologist Brock Fenton told National Geographic that the American bats' extremely high tolerance probably evolved as it allowed them to consume fruits that other animals weren't able to eat. 3. Tree shrews drink "beer" every night, because of evolution. asxsoonxas/asxsoonxas The pen-tailed tree shrew hits the "bars" of the rainforest every night in their native Malaysia, according to a 2008 study published in the Proceedings of the National Academy of Sciences. Their poison of choice? Fermented palm nectar, which has an alcohol strength similar to beer. They spend about two hours per night – every night – boozing it up. Remarkably, they don't get inebriated, despite their small stature. Robert Dudley, physiologist at the University of California, Berkeley told National Geographic that there may be some "positive effects" to alcohol consumption, like protection against cardiovascular risk and more food intake due to the "munchies." Although the shrews can metabolize alcohol much better than their human counterparts, they are theorized to be very similar to the common ancestor of all primates, including humans, which existed more than 55 million years ago, according to a 2005 study published in the Proceedings of the National Academy of Sciences. Keep in mind, humans only figured out how to brew beer about 9,000 years ago. But this study implies that we could have been boozing it up since the beginning of time. Dudley suggests that our ancestors may have inherited this desire to drink alcohol in order to keep our calories up. So, beer saves lives. And possibly all of humanity. 4. Vervet monkeys steal cocktails from humans. Oleg Eliev / EyeEm/ Vervet monkeys in the Caribbean began their addiction to alcohol 300 years ago when they discovered fermented sugar cane during the height of the plantation era. They developed such a liking to ethanol, that 1 in 5 monkeys prefer drinking alcohol over water, according to a 1993 study published by Pharmacology Biochemistry and Behavior 46. Much like humans, the study discovered that teenage monkeys consume much more alcohol than adults. Lead co-author Jorge Juarez tells the BBC that adults drink less in an effort to be more "alert" and "responsible."About 5% of the population are alcoholics. Some monkeys even dare to steal beverages from innocent humans at beach bars. 5. Rough-toothed dolphins risk their lives getting high off pufferfish. IPGGutenbergUKLtd/IPGGutenbergUKLtd Dolphins are extremely intelligent creatures who will one day take over the world, so it's no surprise that they figured out a way to pass around a 'joint'. Their narcotic of choice? The intoxicating pufferfish, whose poison is, according to Discover magazine, 50 million times more deadly than marijuana, 40,000 times more dangerous than meth, and more fatal than poison from the black widow.One dose of the poison, known as tetrodotoxin, can kill dolphins and humans. It will make you feel numb, tingly and light-headed before causing full-body paralysis, according to the Centers for Disease Control and Prevention. But rough-toothed dolphins live life on the edge. Rob Pilley, a zoologist and producer of the BBC documentary, Dolphins – Spy In the Pod, told the Sunday Times that they filmed the dolphins "acting peculiar" after the mammals had chewed and passed around a pufferfish. Christie Wilcox of Discover magazine is skeptical that the dolphins got high intentionally, considering tetrodotoxin doesn't seem like a "happy high." There's only one way to find out if it's worth it... 6. Bees penalise drunk flyers when they get back to the hive. Christine-E-Russell/Christine-E-Russell Getting a D.U.I. is probably one of the worst things to have on your driving record, but at least you're not a bee who was caught under the influence.Bees can get drunk off fermented nectar, causing flying accidents. Some bees get so wasted they don't even remember how to get home. But, it's even more tragic for the bees that do manage to find their way back to the hive. Entomologist Errol Hassan told the Guardian that some hives impose severe penalties for bees caught flying under the influence – even going as far as attacking the poor, drunken bee. But, apparently it's legal in the bee community to consume nicotine and caffeine. In a 2010 University of Haifa study, bees actually preferred nectar that contained nicotine and caffeine over normal nectar. Luckily for the bees, nicotine is naturally produced by the floral nectar of tobacco trees, while caffeine is found in citrus. 7. The first Bush administration planned to use cocaine-addicted caterpillars to eradicate drug cartels. Manakin/Manakin Caterpillars in Peru and Colombia feed entirely on coca leaves, aka the plant that cocaine is derived from. Researchers at Ohio State University studied the South American caterpillars for 10 years to figure out how they can consume so much cocaine, without, well, dying. The scientists figured that the caterpillar was immune to to the "fun" part of of the cocaine high, meaning they didn't get a rush of euphoria. Ultimately, their research was inconclusive. In 1990, the Bush administration even proposed a plan to unleash these pests on coca plants, to halt the drug trade. But it never happened. 8. The Santa myth probably comes from reindeers who eat magic mushrooms. Nick Dale/Nick Dale There's two things you probably didn't know about Siberia: Reindeers and magic mushrooms are common. So, it's only natural that the animals would seek out magic mushrooms as a food source. Reindeers weren't the only mammals who enjoyed a short trip into outer space. Siberian tribesman loved shrooming it up, and may have been so high that they hallucinated reindeer "flying," biologist Don Pfister told Live Science. In fact, our whole Santa Claus myth may have been derived from people and reindeer who were just stoned. "Whoever heard of reindeer flying? I think it's becoming general knowledge that Santa is taking a 'trip' with his reindeer," Professor Carl Ruck told Live Science. 9. Elephants don't go on drunken rampages. mrisv/mrisv There are YouTube videos claiming to show drunk elephants destroying villages after eating fermented marula fruit.But, here's the thing: According to the BBC, elephants are so huge that it would take massive amounts of marula fruit to get them drunk. In order to actually become inebriated, an elephant would have to eat 400% more fruit than it normally does, without drinking any water.While they may be way too big to get wasted, a 1984 study in the Bulletin of the Psychonomic Society found that elephants could eat enough fruit to become slightly "buzzed." In that state they became lazier when eating and bathing – not exactly rampaging behavior.