Collective strategies are possible within a population. Such situations occur
in nature with birds or fishes in flocks. Such swarm intelligence problems are suitable
for optimization problem-solving. Other co-evolutionary models implicate two
different populations or species which compete. In the predator-prey model, the
predator eliminates the weak prey. We show that such a situation can be transposed to
optimization problems, for which the predator is one of the objectives, and the preys
are feasible solutions. Solving an MOO problem may use different ways. One way
consists of decomposing the initial problem into a sequence of subproblems.
