A successful family (agent) should be interpreted as one that is able to support its members, and hence a high food income level means an agent has procured sufficient resources to split, generating a new agent. When fission occurs the new agent occupies the same site as the parent agent, but is then free to move in the next iteration. The new agent will have the same mobility strategy as its parent and a randomly chosen initial food income value (reflecting the non-heritability of food income).