“…There are three basic relationships among different species living in the same natural environment: (i) competitive relationship [1,2], for example, crops and weeds compete for fertilizer, sunlight, and other resources for their own growth; (ii) reciprocal relationship [3,4], such as rhinoceros birds feed on the parasites from rhinoceroses. For rhinoceroses, rhinoceros birds can get rid of the parasites and warn them when they are in danger; (iii) predation relationship [5,6], as the saying goes, "big fish eat small fish, small fish eat shrimps." Among the relationships of population interaction, the predator-prey system has been extensively studied.…”