Even children know about the invisible, secret and deadly power of poison.

There’s the poison apple that the jealous Evil Queen gives to Snow White. In “Alice in Wonderland,” the Mad Hatter’s erratic behavior is the result of mercury poisoning, an occupational hazard for 19th-century hatmakers who routinely used mercury. Every high school student who reads “Romeo and Juliet” – even the CliffsNotes version – discovers that Romeo dies by poison when he finds Juliet apparently dead.

The Science Museum of Virginia’s new touring exhibit, “The Power of Poison” uses these and scores of other examples to showcase the myriad facets of poison and venom. The exhibition looks not only at stories of natural poisonous and venomous parts of our world, but, more intriguingly, the unexpected ways poison has affected lives, using life-sized theatrical dioramas, interactive stations, multimedia presentations and hands-on experiences.

“The Power of Poison” kicks off with the basic premise that the dose makes the poison by displaying a small bowl of salt; the point being, while salt is essential to life and our nerves can’t function without it, eating even this petite serving could unbalance your body chemistry enough to kill you. Ditto chocolate for dogs. The ingredient theobromine that gives humans a happy boost causes seizures in canines.

Poison depends on who or what you are.

Then it’s on to the dimly lit Choco Forest in Colombia where visitors learn about the role of poison in the natural world. There, poisons are powerful weapons made and used by countless organisms in the struggle to survive, reproduce and fend off attackers ranging from microscopic organisms to insects to vertebrates.

It’s in the forested part of the exhibition that visitors learn about venomous animals who have special glands for manufacturing venom and something sharp — spurs, stingers, spines or teeth — with which to inject it. Of the 3,000 snake species, there are only between 250 and 500 that have venom that can hurt humans, a fact that should be reassuring but somehow isn’t. Even so, it can be unsettling to look at the viper skull on display without feeling a twinge at the sharp, hypodermic-like fangs that deliver venom.

For something just plain weird, check out the carpenter ants exposed to a toxin produced by a fungus that takes control of the ant’s brain, effectively turning it into a “zombie ant.” The toxin makes the ant wander off its trail, bite the underside of a leaf and die, but the really gruesome part is the structure that sprouts from the ant’s head which then disperses fungal spores. It looks straight out of a “B” horror movie, circa 1955.

Leaving the forest, visitors can learn about poison’s role in legend, history and human health through the centuries. Turns out literature loves a good poison angle. Of Agatha Christie’s 66 mysteries, at least 28 of them featured poisoning, from arsenic to cyanide, and hemlock to strychnine. Flaubert’s Emma Bovary committed suicide using arsenic. In Umberto Eco’s “The Name of the Rose,” poison is painted on the pages of a book so that the reader will die. The Toxic Avenger comic series is full of poisoning incidents. Even Harry Potter shows up.

Those seeking an interactive experience have plenty to choose from. Visitors can turn the virtual pages of an enchanted book on toxic plants full of folklore and drawings. Life-size scenarios of poisoning allow visitors to track down clues and figure out what caused the victims’ symptoms. According to Timshel Purdum, the Science Museum’s director of education, it’s all about separating fascinating facts from fantastical fiction while navigating toxic twists and turns.

By the time visitors are learning about painter Francisco Goya’s tortured imagery (lead poisoning from paint, perhaps), Lucrezia Borgia’s arsenic ring, and Nero, who had his own professional poisoner because of the frequency with which he dispatched enemies using deadly potions, it’s clear that poison has always been a part of life on planet earth.

Worth noting is that while poisons and venoms have always been nature’s most dangerous substances, they also have a positive role, both protecting the species that wield them and inspiring the development of cutting-edge treatments and cures using them. Plant toxins and animal venoms have been used in treatments for conditions ranging from coughing to cancer. Making medicines means using poison for good.

“The Power of Poison” engages visitors in countless ways, from a staging of Shakespeare’s “Macbeth,” where three green-faced witches brew a poisonous potion in a bubbling cauldron, to an aquarium where everything swimming around in it is beautiful, colorful and toxic.

Among other things, visitors are bound to leave with new insights into the demise of Cleopatra and the unknown danger from Napoleon’s wallpaper. But it’s a rare exhibition that allows them to imagine a time when a ceramic pot filled with venomous deathstalker scorpions was used as a weapon.

“The Power of Poison” runs through April 19 at the Science Museum, 2500 W. Broad St. Smv.org