Fun Scientific Facts about Halloween

Here are some fun scientific facts behind common Halloween themes.

It’s a Fruit, Not a Vegetable: Botanically speaking, pumpkins are a type of fruit known as a pepo, which is a specific kind of berry with a hard outer rind.
The Original Jack-O’-Lantern: The tradition of carving spooky faces began in Ireland, but they didn’t use pumpkins. They originally carved scary faces into turnips and potatoes to frighten away wandering evil spirits. When Irish immigrants came to America, they found pumpkins were much larger and easier to carve.

Seeing with Sound: Most bats have poor eyesight, but they are masters of navigation. They use echolocation, emitting high-frequency sound pulses (too high for humans to hear) and listening for the echoes that bounce off objects. This allows them to build a “sound map” of their surroundings, letting them “see” a tiny insect in complete darkness.
Why Bats at Halloween? The connection likely comes from the ancient Celtic festival of Samhain. This end-of-harvest festival involved large bonfires. The fires would attract swarms of insects, which in turn attracted bats to feast on them, filling the night sky.

Super-Strong Silk: Pound for pound, spider silk is five times stronger than steel and tougher than Kevlar. It’s also incredibly elastic, able to stretch up to four times its original length.
Hydraulic Legs: Spiders are like little hydraulic machines. They don’t have extensor muscles in their legs (the muscles that push a limb out). Instead, they pump hemolymph (their version of blood) into their legs at high pressure to extend them. This is why a spider’s legs curl up when it dies—the hydraulic pressure is lost.
Liquid Lunch: Spiders can’t chew or swallow solids. To eat, they vomit digestive enzymes onto their captured prey. These enzymes liquefy the prey’s insides, and the spider then sucks up the resulting nutrient-rich “soup.”

You Have Fewer Bones Than a Baby: You’re born with around 300 bones. As you grow, many of these bones (like the ones in your skull) fuse, leaving you with 206 bones as an adult.
Your Hands and Feet are Half Your Skeleton: Over half of all your bones are located in your hands and feet. Each hand has 27 bones, and each foot has 26, for a total of 106 bones just in your extremities.
The “Floating” Bone: There is only one bone in your entire body not connected to any other bone: the hyoid bone. It’s a U-shaped bone in your throat that anchors your tongue and is a key part of what allows you to speak.
Bones Are Alive: Your skeleton isn’t just a static scaffold. It’s a living, active organ. Your bones are constantly remodeling themselves, and you essentially get an entirely new skeleton every 7 to 10 years.

It’s Fun to Be “Safely” Scared: When you watch a scary movie or go through a haunted house, your brain triggers a “fight or flight” response. You get a jolt of adrenaline, your heart pounds, and your senses sharpen. But because your brain also knows you’re not in real danger, you get to experience this adrenaline rush as a “high”—all the excitement with none of the actual peril.
Fear is a Social Glue: When you share a scary experience with friends, your brain can release oxytocin (the “bonding” or “cuddle” hormone). This is why facing a “threat” together, even a fake one, can make you feel closer to the people you’re with.

Candy That Makes Its Own Light: If you go into a dark room and crush a Wint-O-Green LifeSaver with your teeth, you’ll see a tiny flash of blue-green light. This is a phenomenon called triboluminescence, where light is generated through friction or crushing. The wintergreen flavoring (methyl salicylate) is particularly good at converting the UV light from this process into a visible blue spark.