The boys are riveted by antlions.
Nature's deathly misdirection. Antlions trail false pincers from the tail of their thin bodies, so that their prey, ants which come within their grasp, run around to what they perceive to be the end opposite the mouth, in reality right into the antlion's jaws. CHOMP! Dead ant.
I'm actually more fascinated by the traps they build to bring the ants within striking distance. They dig a simple conical pit in loose sand, a funnel shape exactly like what you'd leave if you press your finger into a similar spot and withdraw it straight up. Trickster boys sometimes do just that, to tease those of us who find the creatures so interesting. Wandering ants fall into the funnel, and because the sand is loose are unable to climb to safety. Then they confront the predator.
I scoop a handful of sand, a few inches deep. Sift the sand through my fingers until I find the antlion, like panning for gold.
Like marbles, this is a boys' activity. Girls express zero interest. The schoolyard is effectively divided into female and male zones dedicated to contrasting pastimes. I feel that's a shame, because I love the girls. But girls are easier to encounter than antlions, and marbles are just plain cool. After all this is still only grammar school.