On the drywall above the tile in my shower, I noticed something that looked like a little clump of dirt. Didn't think much about it.

Well today I was showering and I look up at it and I see a bug stick it's head up above the clump of dirty. Two little antenna.

So I finally get a stool and cut away the clump of dirt and there's a bunch of little things squirming around.

Seems like termites to me.

Got in the attic right above the area. Done see anything up there.

Anyone have a good recommendation for exterminators in San Antonio?

Yes, yes they are. You likely have a leak in your shower pan/ walls which feeds them moisture and attracts them into the house. They've worked their way up the walls eating the paper on the back of the drywall and the stud materials.

I'd call a pest control person ASAP, get a couple quotes so you aren't paying through the nose for an outdated control method.

Then I'd do some exploration in the walls to see the extent of the damage, as well as look for moisture in the walls, or the base of the pan area.