Fire ants, Crawfish and Mother Nature

I have five acres of yard to mow. About 4-5 years ago the fire ants were getting pretty damn bad. I would see at least 75-100 hills of them. Only three or four would be considerable size. As I'd mow I'd stop and shake a little Amdro on them. Seem to work on existing mounds but they'd just move to a new spot within a couple of week Didn't pay much attention but there were always three or four crawfish mounds in the yard.

As time progressed over the years up until now, the number of fire ants starting decreasing but the number of crawfish mounds starting increasing. I just finished mowing and only saw about three ant hills but I must have mowed over 60-70 crawfish mounds.

Are crawfish MN's way of controlling fire ants or is this just some fluke? Not complaing because I definitely would rather have the crawfish with few ants.