Hello, welcome to the forum.
I don't know much about Texas ants, but if it is similar to here, just go to a desert in the summer, you're bound to find some!
As far as queens, you'll have to go a day after a rainstorm, and you may find queens.
You live in an amazing state for leafcutter ants, Atta texana, a species I wish I could keep. The queens will be everywhere (if I'm not mistaken in desert after rain as well). What's awesome about texana, is they're polygynous, you can put multiple queens together!
Wish you luck, and I'd love to see your ants.
Interested buying in ants? Feel free to check out my shop!
Feel free to read my journals, like this one.
Atta sp, Camponotus sansabeanus, Crematogaster cerasi, Pheidole bicarinata