I’ve never had any luck at all with ant guards, so this has to be one of the number one tips of the year. If you hang your hummingbird feeders with fishing line, it is too thin for ants to navigate. I used 10#, which is what we had around here, and so far I’ve not had one ant in the feeders. (One note: If the line is too short they can figure out how to get to the feeder. 12″ seems to be plenty long enough) It is quite entertaining to watch them try to figure it out at first and then it’s certainly nice to not have to clean ants, dead or otherwise, out of the feeders all the time.