In the Tough Snake Robot Systems Group, a snake robot without wheels (nonwheeled-type snake robot) and a snake robot with active wheels (wheeled snake robot) have been developed. The main target applications of these snake robots are exploration of complex plant structures, such as the interior and exterior of pipes, debris, and even ladders, and the inspection of narrow spaces within buildings, e.g., roof spaces and underfloor spaces, which would enable plant patrol and inspection. At the head of each robot, a compact and lightweight gripper is mounted to allow the robot to grasp various types of objects, including fragile objects. To measure the contact force of each robot, a whole-body tactile sensor has been developed. A sound-based online localization method for use with the in-pipe snake robot has also been developed. To enable teleoperation of platform robots with the sensing system and the gripper, a human interface has also been developed. The results of some experimental demonstrations of the developed tough snake robot systems are presented.