Economics in nature?
You may want to take a look at Evolutionary Game Theory. Instead of using the regular equilibrium concept developed by Nash, it uses the concept of an Evolutionarily Stable Strategy (ESS).
The idea isn't that players are rational and are choosing strategies given what others are doing to maximize payoff. The idea is: each mutation of that species is "programed" to adopt a particular action (instinct), and when different mutations of the gene interact, it will generate probabilities of survival. Thus, an equilibrium strategy is an ESS, which are the types of actions instinctive to a certain gene type, which will tend to survive and procreate, passing forth the gene.
Game Theory is a field that has had intensive collaboration between Biology and Economics. I am sure you will find some interesting stuff.