The effect of laziness in chasers in group chase and escape model
  The effect of laziness in the group chase and escape problem is studied using a simple model. The laziness is introduced as random walks in two ways: uniformly and in a "division of labor" way. It is shown that, while the former is always ineffective, the latter can improve the efficiency of catching, through the formation of pincer attack configuration by diligent and lazy chasers. 
Makoto Masuko, Takayuki Hiraoka, Nobuyasu Ito, Takashi Shimada
nlin.AO cond-mat.stat-mech