Here is a really fun activity to try with older toddlers or preschoolers. First, head out on a walk around the yard, neighborhood or park for some large smooth stones. Some texture will work, but smooth round ones, ideally with a flat face, seem best. We had a great time on our “rock walk”!
When you get home, heat the oven to 225 degrees (f) (I have seen it recommended as low as 225 or as high as 350, so it probably doesn’t matter all that much — hotter rocks will stay hot longer, though, I imagine) and have the kids help wash and dry them so there is no dirt left on them. Place them on a baking sheet or tray, if you wish lined with foil, parchment or a silpat (though none of these are necessary) and heat for 15 minutes or so.
While you are waiting for the rocks to heat up, peel crayons, if you need to. I try to keep a tub of crayon stubs peeled for coloring on hot trays, and any time one breaks we peel it and put it in there.
Now, the fun part! I set each girl up with a tray lined with paper. We discussed that the rocks were too hot to touch with anything but the crayon. I transfered the rocks with a hot pad or tongs. They still touched them when I set one in front of them, of course, but only once! Then they got to work…