The ants were so bad this year that I had to do something. I went out to see why my hummingbirds had been mia for 2 days when I had just cleaned, and refilled, the feeder only to see a dead ant floating inside the feeder. I looked closer and there was an ant trail going to it. When I grabbed it and flipped it over about 30 dead ants went floating to the top with another 20, or so, dead ones trapped in the inner part. So, I grabbed a 13 gauge wire hanger and printed this. The hole is 2.1mm so made for a 13 gauge wire coat hanger but you could use anything you wish just be sure it will not rust. Hummingbird_Feeder_Ant_Moat-2.sldprt is with the center being hollow. The stl is of Hummingbird_Feeder_Ant_Moat.sldprt I have added a size reduced model, with source, that will print much much faster.Moat goes above the feeder so mount->moat->feeder and you fill the moat with water. This was designed to conserve water so it takes very little to fill it but make sure you only fill it up to about 2mm from the lip in case the ants decide to commit suicide to form a bridge for the rest of the colony to cross over (trust me they do these things for the greater good of the colony).