Today the girls watched an episode of “The Cat in the Hat Knows A lot About That”, it was about beavers , or more specifically how beavers use sticks to build dams.
The girls already know a bit about beavers from books as well as “Build it Beaver” from the “Wild Kratts” television show.
I wanted to take things a step farther so I asked if the girls wanted to build a beaver dam today. They seemed interested, but Ella choose to continue watching shows. Agatha came upstairs to help me get everything ready. She gathered the sticks (shish kebab skewers) and helped me break them to fit our dish. Then we created the ‘river’ and ‘pond’.
When Ella came upstairs we talked about beavers and what kind of creature they are. She told me they’re mammals and why they’re mammals (then she went off on a tangent about the platypus – also featured in “Wild Kratts”). We talked about their teeth and why they build dams. Agatha told me what we needed to build the dam: sticks and mud.
So we made our mud (cornstarch and water) and prepared to make our dam.
After we made the dam, and the girls were satisfied, we tested it.
It was not what you’d call water tight. It leaked. The girls loved it! They eagerly used more sticks to fill the holes. They added mud and more sticks. And retested. Our dam never did work the way it’s supposed to, but the girls still had fun.
Ella hypothesized that beavers enjoy building dams, so would continue working to plug holes and if new holes formed they’d just go right on working. Though she also clarified that they wouldn’t work all day, they’d have to stop to eat and sleep otherwise they wouldn’t have the energy they need to continue working. : ) I suggested that beavers swim under the water to see where the holes were, and can plug the holes at the very bottom.
Ella tried several other methods of dam building. She created one of lots of mud and few sticks, another of lots of sticks but very little mud. She created one on the table (not in the ‘pond’ dish we’d been using). She also created one made solely of our ‘mud’. The one made only of mud held the best; only small trickles got through.
Ella hypothesized that if we waited long enough our mud would just wash away, we needed the sticks to hold it in place, just as we needed the mud to hold the sticks.We didn’t test her theory because she wasn’t interested in KNOWing the answer.
As we cleaned up we talked about the special properties of our mud. Ella enjoyed how she could plop it on the table (or floor) and it spread out like a liquid, but when you tried to pick it up, it was hard like a solid. I asked her a few questions to see if she understood the different phases (gas was a bit tricky, but otherwise she’s got it). Then I asked her what our mud was. She thought and decided it was a liquidy solid. Sounds good to me : )