Dear Rob, No pikes, though I am in your debt for the idea. I used the simple expedient of right marker, left marker, front rank, back rank to inscribe a traezoid in the dirt and define the coverage of the 90mm lens. Then I ordered them to stand within marked space. Those who poked over the line were Tazered and pushed back. The children cooperated better than the adults - possibly because they are smaller and easier to frighten. Some of them are still there and it has been a week. Uncle Dick