The Fox Hunting predator-prey model is the same as I have posted in hsc.fed.wiki.
The nodes are of three types, Const, Funct, and Funct/integrator. The model is strongly decomposed where many nodes accomplish one thing.
We try refactoring into two node types, Sum/integrator and Delta. A Delta accumulates influences and applies this to the benefit or detriment of Sums.
Incomplete sketch of Predator-Prey model.