Kirman's ant colony model

There is an interesting phenomenon concerning behavior of ant colony. It appears that if there are two identical food sources nearby, ants exploit only one of them at a given time. The interesting thing is that used food source is not certain at any point of time. At some times switch between food sources occur though the quality of food sources remains the same. In 1993 Alan Kirman proposed that this could happen due to importance of herding behavior in ant colonies [1].