To investigate differences in cockroach “personalities,” specifically the degree to which individual roaches prefer to stay close to a wall or venture into open areas, researchers at Université libre de Bruxelles in Belgium conducted an experiment in which adult male American cockroaches (Periplaneta americana) were placed in a small arena under a light. The researchers observed and measured the position, orientation, and wall contact of each roach before and after turning on the light. Their results showed that cockroaches that stayed close to walls were slower to react to light than those that preferred the center of the arena. (Image originally published in Laurent Salazar et al 2018, Journal of Insect Science)