It wasn't until I stumbled upon this video that I remembered doing this exact thing as a child at camp. Ants are fun.
And its not just as an Etch-a-Sketch that make ants a great choice for a kids toy: There's also the fact that they have properties similar to the Gak and cornstarch+water playthings of our youth. Piles of Ants as a toy. Get on that, someone.
[via Tastefully Offensive]