They are all breeding and military-aged men.
I heard a border patrol agent on a talk show yesterday - he said the cartels control 100% who comes across the border - and are importing TONS of drugs.
What they do is create a diversion with women and children along one area of the border - which sends all the agents scrambling over to that area. While the agents are busy looking elsewhere, the drugs come across unimpeded.
This, of course, is illogical... if you aren't guarding the border you have NO IDEA how much drugs are coming in.