Category Archives: Science Craft

Science Craft: Worm Fun

wormsOur second Science Craft of the summer stretched what it means to be a “craft” a little, but we all had fun, so I don’t think anyone cared.

I bought several dozen nightcrawlers from a bait shop to bring to the library. To begin the program I talked about earthworms, their physiology, habitat, and benefits to the soil. Did you know that many earthworms in North America are invasive species from Europe? I love that my job lets me learn so many new things.

Part two of the program was worm racing! I followed the ideas on this website for my races. I already had a roll of plastic table cloth material, so I covered all of the tables with that, then used a marker to make one small and one large circle. After spending a few moments having fun just holding the worms, and after some instruction on safe ways to handle the worms (squeezing = not a good idea), the children were instructed to put their worms in the inner circle, and the worms would “race” to see which worm made it to the outside of the outer circle. The original website’s circles were very large, and I was worried that my worms would not be active enough, so I made my circles much smaller. It turns out that I shouldn’t have been worried. Not only were my nightcrawlers much larger than the worms the original poster was using, but they squirmed around quite a lot. In a way the smallish circles worked out well, because each table got to have multiple very quick races, but if I ran the program again, I would use larger circles.

A worm painted masterpiece.
A worm painted masterpiece.

Next we painted with the worms. After much internet poking around to assure me the worms would be fine, as well as some quick trials runs of my own to double-check, I was assured that the worms would survive. We dipped the worms in nontoxic paint and then put them on the paper. As they wriggled around they painted the paper. There were bowls of cool water to rinse the worm off so that more than one color could be used. (I emphasized several times that worms breathe through their skin so rinsing should be quick.) The younger children in particular were very taken with the idea that the worms were painting a picture for them.

I provided little plastic cups with lids (the sort that I usually put paint inside for craft programs) so that anyone who wanted to take their worm home could do so. As far as I could tell we didn’t lose any worms to squeezing, though I can’t speak for what happened once they got home.

Science Craft: Ice Cream in a Bag

The summer has started and the library is awash with children. Tuesdays have traditionally been craft days for school aged children during the summer, with the crafts following the theme of the Summer Reading Program. This year’s Fizz, Boom, Read theme means I chose crafts that are at least marginally related to science. Sometimes this means that I had to stretch exactly what a “craft” is, but we’re making it work.

Our very first Tuesday Craft was Ice Cream in a Baggie. If you’ve never done this before, believe me, it’s worth it! The kids were thrilled about the ice cream and the parents were fascinated. I could tell that some of the adults were skeptical that it was going to work, and then amazed when it did. The kids, of course, never doubted for a moment.

Before we started I gave a little talk about how ice forms, using some of the children as volunteer water molecules. I then explained the effect salt has on ice, and how using salt lowers the freezing point, creating an even colder icewater solution. This is the key to making ice cream in a baggie.

So how does it work? First you get a big gallon sized baggie and put in ice and salt. I hadn’t thought to measure the ice and salt the way that I measured the ice cream ingredients, but no one had any problems, so apparently there’s a lot of leeway. I’d say the average child used a little less than two cups of ice and maybe a half cup of salt or less. Kosher or rock salt or the salt you can buy for ice cream makers are best, but table salt is much cheaper and works just as well. We used table salt without any problems.

Next you get a smaller baggie, pint or quart size. Into this second bag you put 1/2 C of whole milk (you can also use cream or half and half, but milk is cheaper when you’re buying for large crowds), a splash of vanilla (I had the children use the 1/8 tsp), and sugar. Because I had more measuring cups than I had measuring spoons I had them put in “a little less than 1/4 C” which made for some very sweet ice cream. In ideal circumstances I probably would have used about 2TB of sugar. But none of the children complained that their ice cream was too sweet, imagine that!

Next you seal the small baggie. Then check to make sure it’s sealed. Then triple check to make sure it’s really, definitely, absolutely sealed. After that you pop the small bag into the larger bag, close the larger bag, and shake, shake, shake. I’d intended to sing some shaking songs, but the noise of dozens and dozens of shaking bags was so loud that I didn’t even try. It takes about five minutes of shaking (and there were a lot of parents who ended up doing the shaking, so thanks parents!) and then the solution turns to ice cream! It’s a softish ice cream and a little grainy (using cream would have helped smooth it out) but delicious nonetheless.

While I did not add any flavorings other than vanilla, I have done this activity in the past with other flavorings. It’s easy to add a squirt of syrups intended for flavoring milk. If you want to add more solid flavors, such as strawberries or broken up oreos (my two favorites) then you need to freeze those additions ahead of time or the ice cream won’t freeze properly.

No pictures today because I was too busy running the craft.