Formicidae (Ants) Insect Adult Pictures

I had a great morning fishing to flying ants in the Catskills on September 5th. At least a few fish were rising steadily in every pool on my selected stretch of the Neversink, and flying ants were abundant in the air and on the water for hours.

There were two types of ants which I collected and photographed this large, rusty-tinted variety and a smaller type. I'm curious: were they two different species, or different-looking males and females of the same species?

Many ants were descending to the water in pairs, presumably mating. I hadn't yet noticed the difference in sizes, so I didn't check to see if each pair had one large and one small ant.