Biology can tell some of the most compelling stories of Economics at work. This post by Carl Zimmer is a great example of the problem of Public goods. The question here is why some of these critters "willingly" sacrifice themselves so that others may breed.
The theory of altruism pioneered by Haldane and Hamilton can explain such behavior when the parties are closely related, but not when they are totally unrelated. Any gene that leads to such behavior would quickly die out. "The evolution of virtue" by Matt Ridley had a great discussion of such issues.