Those aren't generally spiders.
To the OP: You're far too late. This community spiders have already been found in South America, Central America and now within the good 'ol USofA.
Here's another thought:
Quite a few species of ants, most notably the Argentine, have evolved into the development of multi-queen mounds encompassing hundres and hundreds of sq miles. Im talking literally large enough to be in two countries. A single, multi queen colony! (Yes, it is possible to test ants to see if they are from the same mound.)
If you want to be amazed, look up the argentine ant and the locations of their super colonies and marvel at their size. BTW, they're in the US, now, too. As a matter of fact, I found a HUGE location near my house in Texas and had to report it. I won't get into all that here, though. No time, man.