This paper reports on an underwater wheeled robot designed to locate chemical sources by mimicking the behavior of a crayfish in still water. Crayfish in search of food generate water currents by waving their fan organs, i.e., the maxillipeds, to collect the food odors from the surroundings to the chemoreceptor organs. Similarly, the robot waves the arms mimicking the maxillipeds, and generates a flow field to collect chemicals to the four sensors. The generated flow field brings chemicals released from different areas to the different sensors. Therefore, the direction of the chemical source can be determined by simply comparing the sensor responses. Although the maximum range for drawing the chemical is approximately 5 cm, the chemical sensing ability of the robot is significantly improved. Experimental results show that the robot can localize a chemical source by employing the actively generated flow field.