Free Halloween Science Coloring Pages!

Here are some fun science-themed Halloween coloring pages for your little ones…or you!

Halloween Coloring 2017 (Click there to download the PDF, or alternately you can copy the JPG images below). Feel free to share online, but please link back to this page 🙂

This year, we chose to do pumpkins, bones, and spider webs– the quintessentials of Halloween decorating. Below is a little biochemistry about each topic and some activities to do with each page!



Our DNA is the instruction manual for our cells. DNA may seem like such a complex thing, but it really is only a string of 4 different molecules attached together to make a code. All life on Earth uses these same molecules. When a cell needs to do something, like grow or move, it makes large molecules called proteins to accomplish these tasks. Our DNA is the instructions to make these proteins (side note: we are finding there is more to our DNA code than just this, but this is an incredibly important function). If you compare a human genome (sequence of DNA molecules attached together) to that of a pumpkin, you would find that we share 75% of the sequence! This suggests we each have proteins that do similar things, and that’s true. But, we are animals and they are plants, after all, so how can this be? As you can imagine, that leftover 25% is coding for some pretty important stuff like…I don’t know…A BRAIN? A HEART? Also, some of our proteins are similar in some ways (so we’ll share some part of the DNA sequence) but they will differ in incredibly important ways that separate us from other organisms.

Anyways, these “comparative genomics” facts are fun and humbling to hear. We share over 99.9% of our DNA with other humans and 96% with chimpanzees. 60% is the amount we share with both chickens AND bananas. These fun facts might be a good starting point to discuss with kids how we are different from other organisms, and how are we the same.


Source: National Human Genome Research Institute

More info: National Human Genome Research Institute

More info for scientists about shortcomings of comparative genomics

Pumpkin Science Activities

  • Easily extract DNA from your pumpkin! (Links to a tutorial from
  • When you throw out your jack-o-lantern, put it somewhere where you can watch it decompose. Take notes about what happens and when. Check next summer to see if any seedlings have sprouted!





Biological mineralization, when an organism causes inorganic salts to crystallize or precipitate, happens more frequently than you think! Humans are able to make bone and teeth, but did you know there are little bacteria that can make magnetic crystals to help them navigate? Other examples of biomineralization include sea shells, pearls, and egg shells! Our bones are made of a complicated network of cells that work together to mineralize organic tissue, but the actual crystallization happens on a ubiquitous protein called collagen. You may have heard of collagen in beauty product commercials. It is a protein made of three strands that wrap around each other, forming a triple helix, and is responsible for give tissues elasticity. You have cells in your bones called osteoblasts that send out perfectly arranged networks of a certain type of collagen. This forms an ordered network on which to grow the crystals in your bones. Osteoblasts then help to send out calcium phosphate over the collagen network. Calcium phosphate is a water soluble form of calcium derived from the foods you eat. The arrangement of atoms on parts of the collagen network sort of act like a magnet to trap and carefully arrange the calcium into a crystal form called hydroxyapatite. The beautifully ordered network of flexible collagen and stiff hydroxyapatite is what gives your bones resilience and strength. It is a truly amazing process that I definitely took for granted until I learned more about it!

Sources: Journal article (behind paywall, sorry)

For general overviews from Wikipedia: OsteoblastsBone Matrix

Bone activities




Spider Webs

Spider silk is a surprisingly strong, extendable, and resilient material, and is a true testament to the power of evolution. If you had an equal weight of steel and some types of spider silk, they would have similar strengths (but that would be a lot of silk, wouldn’t it?). Scientists have tried to make spider silk in large quantities, but they haven’t been very successful yet. Recently, some scientists made a model of what the proteins in spider silk may look like, and tried to help explain what gives the silk such strength and stretch. In the coloring page, you can see a drawing of the protein.  (Keep in mind when you’re “looking” at a protein like this, the lines are only a couple of atoms thick!! Proteins are very small!) In the middle of the protein are straight, parallel lines. Biochemists call these “beta-sheets.” You can think of them as little sheets of velcro. The atoms in them are so attracted to each other, that they stay stuck even when something is pulling on it (like a fly trying to get away!). These structures are what may give spider silk its strength. On the ends of the protein are squiggly tangles of lines. You can think of these like curly hair– that when you pull them they stretch out, but when you let go, they snap back to how they were. This is what may give spider silk it’s elasticity or “extendability.” The proteins are attached end to end in a repeating pattern to form a very very thin strand, then many of these strands of protein are wrapped around each other to create a strand of spider silk. It is amazing that characteristics we see on the large scale can be traced all the way down to molecular and atomic origins, isn’t it?

Spider Activities

  • Not science, but I LOVED doing this as a kid: tape or tie yarn in a web-network in a hallway and have the kids be flies and try to get through without touching the yarn.
  • Go outside and try to find some spider webs! Did the web catch any food?
  • Here is how to catch and preserve a spider web (link opens to a tutorial on the blog Sun Hats and Wellie Boots)
  • When I was young, a friend captured two spiders for a science fair. One he left alone and gave water and flies for food. The second, he gave flies, but vodka to drink. He then compared their web-making abilities…you can guess what happened, but still might be fun to try.

Click here to download the Halloween Coloring 2017 PDF!

Let me know how you like them and send pictures of your kids’ creations on Twitter, Facebook, or Instagram!

Happy Halloween!

If you’re interested in checking out any of our books, find them here! All of them are available on Amazon.

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