Leiningen, the titular protagonist of "Leiningen Versus the Ants," is a strong and wilful character. His most admirable strength is his insistence on fighting the ants with his men; while he could have instructed them to fight alone, and they would have agreed because of their respect for him, Leiningen is on the front lines with them at all times, directing and helping as they battle the ants. At the end of the story, as the ants seem poised to overwhelm the plantation, Leiningen decides to dam the river, an action of great risk:
"Now one of you might manage to get as far as the weir -- but he'd never come back. Well, I'm not going to let you try it; if I did I'd be worse than one of those ants. No, I called the tune, and now I'm going to pay the piper."
(Stephenson, "Leiningen Versus the Ants," classicshorts.com)
The ants have been shown to be a mob, moving and unthinking with no thought for their fellow ants. By taking the final blow into his own hands, Leiningen shows himself to be of a higher order than the ants, willing to sacrifice himself instead of ordering someone else to a possible death. Leiningen's self-reliance is an example of his individualism and refusal to place his life and importance over any other human.