Spooky Halloween STEM ideas

Halloween is just around the corner. Bring some real STEM science into you house by doing some seriously fun, and spooky, science with your kids!

Halloween STEM activity ideas:

Make a mummy

Nothing says spooky Halloween science like making a mummy at home. It is easy to make your own mummy, you just need lots of salt, some baking soda, and a small chicken. If you aren’t interested in mummifying a chicken, you can do the same experiment with a vegetable like a tomato. Over the course of the month, your chicken (or tomato) will lose water to the natron, a mix of salt and baking soda. After about 4 weeks of changing the natron regularly, you will have a dried out chicken ready to wrapping! Use some gauze or strips of cloth to wrap your DIY mummy, then give it a name and backstory!

We celebrated wrapping our chicken mummy with some delicious mummy cupcakes! Baking is always a great hands-on┬ámath and science activity. All that measuring, counting, fractions, mixing, and chemistry lead to a tasty treat and memorable science where kids don’t realize they are learning. We decorated the cupcakes with white frosting and candy eyes which gave them a super cute look!

DIY chicken mummy osmosis science

Slime Pumpkins

Pumpkin carving is a big hit in our house. It helps our girls practice fine motor skills in their drawings, gross motor skills in some of the cutting, and a little hands-on experience with selected power tools. Amp up your pumpkin carving experience with a little science, and a nice lesson in hand washing. When you get your pumpkins get an extra pumpkin to slime because the slime pumpkin will…well, it will get slimy, and gross, and disgusting.

When it is time to carve your pumpkins open up the slime pumpkin first. Make sure not to wash any hands before this pumpkin. Scrape out the insides letting your hands (and all of their germs) get into the pumpkin. You can carve a ghost or something fun and easy onto this pumpkin, and then just set it aside. Now, before doing your other pumpkins be sure to wash your hands! Carve away. A gentle bleach wash after carving your real pumpkins will help them last longer – and also is a great opener to what hand washing and bleach do.

Set your pumpkins outside, just like you normally would. After a few days take a look at them and see if you notice anything. Likely the pumpkin that was scraped out with mucky hands is growing things, while the other, more prized, pumpkins are happily looking bright and orange. Slowly the slime pumpkin will turn into a moldy slimy mess and you can talk with the kids about what might be happening. Why are things growing there more easily?

make a slime pumpkin for spooky STEM

Zombies and Bloodsuckers

There is a shocking variety of zombie and bloodsucking animals. If you have a kid that loves the creepy crawly creatures this is the perfect time to start up a little research project. Go to the local library to find books on these devilishly spooky insects, make large drawings of them, create a model, or write a zombie-tastic story!

science of halloween zombies


Stir a Witch’s Cauldron

Bubbling, frothing, and smoke all come to mind when I think of potions being made in a witch’s cauldron. For this project, you need a plastic bowl and plastic (or wooden) spoon. It is important not to use metal in this project. Go to your local grocery store and pick up a few pounds of dry ice. Then let your kids mix up mysterious potions as you add dry ice and water to the bowl. Encourage them to add liquids, solids (like maybe a toad?), coloring, etc. A little bubble juice will make large popping smoke-filled bubbles. You can talk about why the dry ice is bubbling (because the water feels so hot to it that it is boiling off), what the smoke is from (it is the gaseous form of carbon dioxide, basically the steam from the dry ice), and why it likes to fall to the ground (because carbon dioxide is heavier than air, one reason why the detectors need to be low to the ground).

halloween STEM activities Stir a witch's cauldron

Make Edible Blood

Yick! Eating blood sounds awful, but when this activity is done, you will be ready to dive in and chomp it up! To make edible blood for this spooky Halloween stem activity you will need yellow jello, mini marshmallows, chopped up cherries (or another small red candy or fruit), and purple nerds. Each item is a component of our blood, and this is a great way to talk about the role each piece has in our bodies.

Yellow Jello: The yellow jello represents the liquid part of our blood, the plasma. Plasma color ranges from light yellow to dark orange and contains the water, salts, proteins, and enzymes that get transported around our body. Plasma makes up a little over half of the contents of our blood (55%).

Mini marshmallows: The mini marshmallows represent the white blood cells. White blood cells are the backbone of our immune system protecting us from foreign invaders (like splinters) and illness (like the flu). You don’t need to add too many of these into your edible blood – white blood cells make up only 1% of the total.

Chopped cherries or Red Hots: These represent the red blood cells. Red blood cells account for ~40% of the total blood makeup, so choose a red candy or fruit that you like! Red blood cells are responsible for delivering oxygen to our muscles. Adults create more than 2 million new red blood cells every second!

Purple Nerds: Purple nerds represent the purple colored platelets in your blood. Smaller than red blood cells, platelets are tasked with clotting injuries, an important role if we don’t want to bleed to death from a paper cut.