I got this idea from the AP economics teacher Facebook page. If you are not a member, I would strongly suggest it. It is a great resource to ask questions, bounce ideas, and be in a community with fellow economics teachers. Antony Davis, who has done a number of videos for the Learn Liberty Series, and is a good friend of mine, posted this video.
His position is this: An ecosystem is actually an economy where predators are consumers, prey are producers, and genetic mutation and behavioral adaptation are entrepreneurs.
This a fun way to show economic ideas through nature, or even dispute Adam Smith's statement in, "The Wealth of Nations." that, “It is common to all men, and to be found in no other race of animals, which seem to know neither this nor any other species of contracts.” WON Book 1 Chapter2.
Either way, a fun bell ringer.