We made a mud pie yesterday for science. We're studying fossils this week, so the experiment was to make a mud pie with some seashells, rocks, sticks, etc, mixed in with mud. Then we let it dry for a day (no problem with that, here in drought-stricken Texas), and today we broke it apart and looked at the impressions we made. The seashells made the prettiest "fossils," with their finely detailed lines etched in the mud. The instructions said that soil with heavy clay content worked the best. No problem with that either. Our soil is probably about 90% clay!
All 3 kids loved this experiment, though my little boy refused to stick his hands in the yucky mud as we mixed it up yesterday. My middle child poked around in it a bit, but my oldest, princess-y girl dug right in and got mud almost up to her elbows!
The problem came during clean-up time. I was washing off the middle child in the kitchen, so I sent my oldest to her bathroom. She came back in a few minutes to tell me the sink wasn't draining. Must have been that clay soil. I poured almost a whole bottle of Liquid Plumber in the sink, and let it sit for about 6 hours - still completely plugged. It looked disgusting too, with half-dissolved mud, gel-like liquid, and soapy water all mixed together. My husband eventually got the toilet plunger out (though I know the Liquid Plumber bottle says not to do that), and got it flowing again after just a few minutes. That sink has problems anyway, and is connected somehow to the air conditioner as a drain, so I think some sort of vacuum had built up and it wasn't really the Liquid Plumber's fault. But at least it is fixed now, and running smoothly!
My oldest and youngest worked well together uncovering the "fossils" too. The middle child stayed inside with me, as it was way too hot and humid outside, even at 11am. My oldest carefully picked apart the mud pie and found all the fossil impressions (and showed us through the sliding glass door), and then gave the leftover pieces of dried mud to my youngest, who proceeded to throw them all over the porch to watch them crumble to pieces. Great fun!