20+ Easy & Fun Halloween STEM Activities
This is a roundup of 20 Halloween STEM activities that turn pumpkins, slime, and spooky props into hands-on science. The dancing spiders experiment is the one I would steal for my own kitchen table, static electricity making little spider legs twitch is the kind of simple magic that gets kids asking “how” without any prompting. These ideas mix fizzing potions, oozy slime, and real science concepts so the learning sneaks in while everyone thinks they are just playing with pumpkins and ghosts.
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Pick a couple, spread them out over October, and let the kids repeat the ones they like. Most of these use stuff already sitting in your pantry or the Halloween bin, which is half the appeal. Toddlers will be happy squishing slime and watching a potion foam over the side of a cup. Older kids will start asking why the vinegar and baking soda do that, and you can go as deep into the answer as they want.
For more spooky sensory fun, check out Halloween Sensory Bins, Halloween Sensory Play Ideas, Halloween Spider Sensory Bin, and Fizzy Jack O Lantern Potions.
Fizzy Jack-o-Lantern Potions: Halloween Sensory Play
Grab a plastic bottle and get ready for bubbling orange Halloween magic! Kids will love drawing a spooky jack-o-lantern face, mixing in glitter, and watching the fizzy overflow happen again and again. It’s such a fun hands on science activity for toddlers and preschoolers craving a little Halloween sensory fun.
Pumpkin Skittles Experiment
Start the spooky season with this fun and easy pumpkin Skittles experiment that kids go crazy for! It’s also a super quick idea, perfect for when you are short on time!
Pumpkin Volcano Experiment by Messy Little Monster
Turn a small pumpkin into a bubbling volcano with this fun Halloween science experiment. Kids combine baking soda and vinegar inside the pumpkin to create a colorful fizzy eruption while exploring the basics of chemical reactions.
STEAM Halloween Magic Trick by Barley & Birch
Make some DIY magic using the power of magnetism. Victims will be convinced that this bone is possessed when it keeps sliding out of its box on its very own, when it’s really just a case of reversed polarity. .
Bowtie Pasta Bat Slime by Cultivating Brilliant Minds
This Halloween slime activity combines fluffy slime with bowtie pasta to create a fun bat-inspired sensory experience. Kids can enjoy squishing, stretching, and playing with the spooky slime while adding a creative Halloween twist to sensory play.
Skeleton Bridge STEM Challenge by Little Bins for Little Hands
Challenge kids to build a bridge using cotton swabs as spooky “bones.” They’ll plan, build, and test their structures while exploring balance, strength, stability, and weight distribution.
Flying Ghost Halloween Kids Activity by A Little Pinch of Perfect
Make a lightweight tissue paper ghost appear to fly using a balloon and static electricity. Kids can rub the balloon on their hair or a wool shirt, then bring it near the ghost and watch it lift and move without being touched.
Magic Halloween Potions Science Activity by Taming Little Monsters
Kids can create colorful bubbling potions using water, food coloring, and dry ice. The dry ice creates an impressive foggy effect while giving children a chance to explore sublimation and experiment with variables such as water temperature and the amount of dry ice. Adult supervision is required, and dry ice should never be handled with bare hands.
How to Make Oobleck by The Best Ideas for Kids
This simple oobleck activity turns cornstarch and water into a fascinating non-Newtonian fluid that can behave like both a solid and a liquid. Add green food coloring for a spooky witch’s brew and let kids test how pressure changes the mixture.
Pumpkin Science Experiment by Hands On Teaching Ideas
This pumpkin investigation gives kids a chance to observe how temperature and location affect decomposition. Children place pumpkin seeds and pumpkin pulp in containers and leave them in different environments, then make predictions and compare the changes after a week.
Spooky Diving Ghost Experiment by STEAMsational
Ready for the ultimate combination of spooks and science? Recreate the cartesian diver experiment, but with a spooky, floating ghost, who relies on the forces of pressure, buoyancy, and density to magically fly up and down.
Dancing Spiders Science Experiment by Finding Myself Young
This is a super simple experiment to set up, but kids love it every time. Spiders dropped in a clear fizzy liquid such as club soda will start to spin, jump, and dance around as the CO2 bubbles attach to them.
Pumpkin Patch Paper Plate Marble Maze by Buggy and Buddy
Kids design their own pumpkin patch marble maze using a paper plate, creating paths, loops, vines, and pumpkin obstacles for a marble to navigate. As they tilt the plate to guide the marble, they explore balance and gravity while practicing problem-solving and engineering skills.
Pumpkin Jiggly Slime by Natural Beach Living
This pumpkin-themed slime combines orange slime with real pumpkin seeds for a squishy sensory experience that looks a little like pumpkin guts. Kids can knead, stretch, and squeeze the jiggly slime while exploring its unique texture.
Magnetic Spider and Fly STEM Craft by Kids Craft Room
Kids can make a spider and fly that chase each other around a paper plate spiderweb using magnets. This interactive Halloween STEM craft introduces children to magnetic force while encouraging them to experiment with movement and create their own magnetic games.
Erupting Halloween Pumpkin Experiment by Living Life & Learning
Turn small pumpkin containers into colorful, bubbling volcanoes with this easy Halloween science experiment. Kids combine baking soda, vinegar, dish soap, and food coloring to create foamy eruptions while learning about chemical reactions and carbon dioxide gas.
Halloween Thaumatrope by Red Ted Art
This clever Halloween paper craft introduces kids to the science of optical illusions with a homemade thaumatrope. As the paper disc spins, two separate drawings appear to become one, making a ghost seem to appear inside a cage or window.
Fizzing Pumpkins Halloween Science Experiment by Finding Myself Young
This is a perfect STEM activity for a preschooler, although it does require some planning ahead. Make an orange baking soda paste and freeze it in a pumpkin-shaped ice tray overnight, then break out the vinegar droppers.
Witch’s Brew Slime by Sugar, Spice and Glitter
Kids can mix up a spooky batch of stretchy, oozy slime inspired by a witch’s magic potion. The easy slime recipe can be customized with purple coloring and fun Halloween mix-ins, making it a fun sensory activity with a bit of pretend play.
Geoboard Gourd by Parenting Chaos
Turn a real gourd or pumpkin into a creative geoboard using golf tees and rubber bands. Kids can stretch the bands around the tees to make shapes and patterns while practicing fine motor skills and exploring geometry concepts such as shapes, angles, symmetry, and perimeter.
Halloween Balloon Experiment by Little Bins for Little Hands
Give a classic baking soda and vinegar reaction a Halloween twist with spooky balloons that inflate themselves. Kids can experiment with different amounts of baking soda, make predictions, and observe how the chemical reaction produces carbon dioxide gas that fills the balloon.
Pumpkin Spinning Tops by Buggy and Buddy
Turn inverted wooden spinning tops into jack-o’-lanterns, then watch them flip and spin across a flat surface. This playful physics activity lets kids explore motion, balance, and how different surfaces affect the way their pumpkin tops spin.
