Recently, many studies on swarm robotics are being conducted, in which the aim seems to be the realization of complex task ability by cooperating with each other. Future progression and concrete applications are being expected. The objective of this study is to construct an attractive system by using multiple mobile robots. First of all, multiple mobile robots with six PSD (Position Sensitive Detector) sensors are designed. The PSD sensor is a kind of photo sensors. A control system is considered to realize such a swarm behavior as Ligia exotica by using only information of PSD sensors. Experimental results show interesting behaviors of multiple mobile robots such as following, avoidance and schooling. The proposed system was intriguingly demonstrated to high school students in OPEN CAMPUS 2010 held in Tokyo University of Science, Yamaguchi.