A hexapod robot was developed to explore an agricultural field and gather agronomical information such as soil nutrients and plant growth. in addition, a sensor device for the robot to track a gas source was developed. The sensor device consisted of a CO2 gas sensor and an anemoscope. The gas sensor detected the concentration Of CO2 in the surroundings, and the anemoscope indicated the upwind direction from the robot. An indoor test was conducted during which the hexapod robot tracked windward direction using the sensor device. According to the results, the hexapod robot with the sensor device successfully localized a CO2 source that was in the upwind direction. The robot paused on the spot under windless conditions, and walked windward as soon as the wind started blowing again. (C) 2008 Elsevier B.V. All rights reserved.