Janie Zapata, 8, at her home in Donna, Texas, outside McAllen in the Rio Grande Valley near the U.S.-Mexico border, April 9, 2012. Roughly 500,000 Texans live in "colonias," or neighborhoods, along the state's 1,248 mile border with Mexico. About 100,000 of them are children. Watch ABC's John Quinones full report, "Hidden America: Dreaming Off the Grid," TONIGHT on "Nightline" at 11:35 p.m. Scott Dalton/Zuma Press For ABC News