In this paper we present an approach to controlling transitions in multirobot tasks which have been modelled as a linear series of steps. A box-pushing task is described as a sequence of sub-tasks with a separate controller designed for each step using finite state automata theory. Perceptual cues are formed by concatenating binary variables which represent locally sensed stimuli into boolean vectors used to specify transitions between sub-task steps. The approach is designed for a redundant set of homogeneous mobile robots equipped with simple sensors and stimulus-response behaviours. A set of perceptual cues used in box-pushing are designed and tested on 10 physical mobile robots. It is argued that perceptual cues and finite state automata offers a new approach to environment-specific task modelling in collective robotics.