A wireless, camera-equipped robot is displayed by the U.S. Border Patrol during a briefing in Nogales, Ariz., Tuesday, Jan. 14, 2014.
With more than 75 underground drug smuggling tunnels found along the border since 2008, mostly in California and Arizona, the U.S. Border Patrol is utilizing the robots to assist in their search. (AP Photo/Brian Skoloff)
U.S. Border Patrol Agent Ryan Grimm demonstrates how a robot is used to navigate a drainage canal along the border fence during a briefing in Nogales, Ariz., Tuesday, Jan. 14, 2014.
This July 8, 2004 file photo shows a Mexican federal agent crawls through a hidden tunnel, presumably used to transport drugs from Mexico to the U.S.
This Jan. 25, 2006 file photo shows a Mexican federal police officer reaches down to assist a Mexican army soldier after climbing up a ladder from a sophisticated clandestine tunnel that passes under the US-Mexico border in Tijuana, Mexico.
This June 4, 2010 file photo shows Mexican army soldiers standing guard next to a tunnel at the border wall in Tijuana, Mexico.
This file photo provided by the San Diego Tunnel Task Force shows the entrance to a cross-border tunnel in San Diego.