Robots are now being employed by the U.S. Border Patrol as part of its efforts to protect the 2,000-mile border with Mexico.

The robots are used to explore tunnels found by the agency, which are used to smuggle drugs or even people into the country. Exploring the tunnels can be dangerous, so robots are being sent in before agents to check for threats and to make sure the tunnel is structurally sound enough for people to enter.