If you have fire ants, like I suspect that McBrown does then be advised that the nest may extend downward to the water table. The 'Hill' or tunnels may also extend outward 100 feet or more in every direction, meaning that one fire ant hill may control an acre or more worth of ground.
However, by either mowing or monkeying with the 'hill' in some other way, it is likely that you can 'encourage' the fire ants to change the location of their hill by up to 20 feet.
But keep in mind that they will only move the 'hill's' location to whichever location that the ants find the most advantageous, not to where you may want it.
The upstart of all this is that unless you buy you chickens from the Caterpillar bull dozier company or else from the Link Belt mining machinery company, chickens are not an end all or do all for exterminating ant colonies.
However if and when a newly bred queen fire ant lights on your lawn, your hens may just gobble that queen up before she has the chance to begin a new colony.