I may try a thin coating if vaseline near the ground as insurance.
UPDATE on ant moats...
The ants were foiled by the moats. Early on, they were so numerous and used to swarming the feeder that they tried to use shear numbers and swimming to overcome the obstacle. A few actually drowned. Then, the numbers dropped precipitously. Now, you rarely see ants. You do gave to keep filling the moats but that's OK by me. I fill slowly to the point where the water is actually above the rim but held by surface tension. It is hot here so it will evaporate in 8-10 hours. Not bad really. Well designed feeder.
BTW, I picked up 2 HummZinger Ultra feeders (made in the USA) after seeing people rave about them. They also have built-in ant moats. I have yet to try them as I have two feeders out and only seem to have one hummingbird thus far...and it seems to visit sporadically.
