Odontomachus are a very common ant in my area, very frequently found nesting in bushes, under rocks, or at the base of trees. I've always thought the ones here were O. brunneus since I'm pretty sure it is the most common species in Florida. But after looking at their measurements, I'm not too sure.
Although these ants do look a lot like O. brunneus, all 4 Odontomachus species in Florida look too small to be these. O. brunneus looks to be about 7mm, and the other three species are around the same, not really surpassing 8mm. But these Odontomachus in my backyard everywhere are easily 10-12mm. I am sure of this, as I have physically measured them with a ruler.