How about the liquid antrid ? Is that effective?

My garden is also teeming with ants - it seems to be the condition of dry
weather that allowed them to breed last year. The recent downpour has forced
some of them to the surface.

I found my letterbox area covered with small red ants. There were also
hundreds of drones - ants with wings - with them. I covered their tracks
with antrid and they seem to have all disappeared.