Evolutionarily, humans are scared of creepy-crawlers and poisonous things. Our fight-or-flight kicks in whenever we’re confronted with something that has more than 4 legs, stares at us with 8 glistening eyes, or exhibits protruding fangs or a stinger. Either you kill that spider or you run away from it, as shudders contort your body and squeals escape your lips.

However, science shows that the venoms of the natural world can actually be harvested as potential medicinal treatments and cures. From using scorpion, bee, and snake venom for cancer treatments to employing venom immunotherapy to treat insect sting allergies, researchers have investigated the therapeutic effects of a wide variety of animal and insect poisons. And it turns out that when used the right way, the poisons that would typically kill us can actually save our lives, too.

“Ironically, the properties that make venom deadly are also what make it so valuable for medicine,” Jennifer Holland writes for National Geographic. “Many venom toxins target the same molecules that need to be controlled to treat disease. Venom works fast and is highly specific. Its active components — those peptides and proteins, working as toxins and enzymes – target particular molecules, fitting into them like keys into locks.”

Thousands of animals are venomous — from snakes, scorpions, spiders, and bees to lizards, octopuses, fish, and snails. Researchers still haven’t studied or unleashed all the medicinal properties of these thousands of different venoms, all of which are seething with various toxins, proteins, molecules, and enzymes that could potentially be used to treat diseases. But below are the current ways that scientists have used venoms in medicine.

Spider Tarantulas produce toxins that are used in painkiller drugs. Photo courtesy of Shutterstock

Spiders

According to a 2012 study out of the University of Buffalo, a particular protein found in spider venom could work as a treatment for muscular dystrophy — an umbrella term for a number of diseases that cause loss of muscle mass and eventual inability to walk, move, or swallow. The study found that the protein helped stop muscle cells from deteriorating, and though it wasn’t a cure, it assisted in slowing down the progression of the disease.

Tarantulas, in particular, have been shown to harbor healing properties in their venom. One 2014 study out of Yale University described a new screening process known as “toxineering” that could sift through millions of spider toxins and find which ones were most compatible in painkiller drugs. They found that one toxin in the Peruvian green velvet tarantula could block chronic pain. Another recent study found that 7 different compounds in spider venom could potentially be used to help people with chronic pain too. Researchers analyzed 206 different spider species, and found that 40 percent of the venoms had compounds that blocked nerve activity linked to chronic pain.

centipede The creepy crawlers that hang out in niches and in your basement may provide scientists with certain therapeutic properties. Photo courtesy of Shutterstock

Centipedes

It turns out that centipedes may be used as painkillers, too. In one study, researchers examined the effects of the Chinese redheaded centipede which injects its prey with venom that blocks a sodium channel protein and ultimately paralyzes its victims. They then tested mice with a peptide taken from the venom, and found that it was comparable to the effects of morphine — the mice were able to tolerate thermal, chemical, and acid pain tests.

Scorpions Scorpions may be some of the freakiest creepy-crawlers on this planet, but their venom has medicinal properties. Photo courtesy of Shutterstock

Scorpions

Similarly to the centipede and spider peptides that are able to interact with sodium channels, researchers found in a 2010 study that scorpion venom too could have painkiller properties. But this isn’t all: researchers also found that scorpion venom could assist in fighting cancer.

Seattle researchers developed something called “tumor paint” out of scorpion venom, which was successful in identifying brain cancer and lighting it up for doctors to see. They re-engineered a specific protein from the Israeli deathstalker scorpion to make it bind to cancer cells, then tied it to a fluorescent molecule that acts as a sort of flashlight or glow to assist in surgeries or identifying cells within the body. “The scorpion toxin finds the cancer cells and drags the flashlight into them and makes them glow brilliantly,” Dr. Jim Olson, a brain cancer specialist at Seattle Children’s Hospital, said, according to ABC News.

Snake Snake venom is already used by doctors in various drugs to treat heart problems and even disorders like Alzheimer's and Parkinson's. Wikimedia

Snakes

Scientists have been studying the medicinal properties of various snake venoms for decades. For example, certain Tunisian vipers have been shown to have anti-tumor properties. Others have antibacterial and painkiller features.

Hemotoxins in snake venom target the circulatory system, and typically attack the body’s clotting ability and muscles. But scientists have also found ways to use hemotoxins for medicine — such as treating heart attacks and blood disorders. Other drugs have been developed from neurotoxins in snake venom, which are used to treat Alzheimer’s and Parkinson’s, as well as stroke and brain injuries; more research will need to be done to better understand the medicinal properties of these toxins.

sea anemone Sea creatures like anemones that contain poison have also been shown to have medicinal properties. Photo courtesy of Shutterstock

Sea Creatures

Deep in the ocean, thousands and even millions of critters lurk way out of our sight. But many of them may harbor potential cures and treatments for diseases in their venom. One study found that sea anemones and core snails produce toxins that could treat autoimmune diseases like arthritis, multiple sclerosis, and lupus.