Maybe they're trying to get their citizens back

So the Mexican army had its 43rd incursion across the border in less than a year, and our State Department is saying it resulted from confusion over the placement of the border, even though they had to go through a hole in a fence to make the crossing.

Y'know, I don't even set foot in my neighbor's yard without being damned sure that it's okay with him him, and I'm fairly certain he wouldn't be too happy if I climbed his fence with a rifle in hand and wouldn't leave until he convinced me I was in fact in his yard.