Just can't stop them

Last year when writing about how these large ants always take over one of my hummingbird feeders, I got some good suggestions about how to stop them.

The "well" on top of the feeder itself is supposed to be filled with water to form a barrier that the ants can't cross. This works for about 10 minutes until the water evaporates. Okay, maybe an hour or two. Still not long-lasting enough to be practical.

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I've tried using soapy water instead and it works longer, but if it rains the soap coats the outside of the feeder and the hummers won't visit.

One great suggestion I got in response to that previous post was to use double-sided tape on the pole to stop the climbing pests.

I didn't have double-sided, but I wrapped duct tape around the pole (sticky side out of course). This worked a little:

You can see that some of these guys made it higher than others. Eventually, they were able to cross the entire strip, regardless of how long it was:

In fact, many ants made it up:

I have no idea why they couldn't find their way out. Do hummingbirds like ant-flavored sugar water?

A gruesome trail of ant body parts remains:

I wonder if woodpeckers removed (ate) the bodies, or if the ants just continued their climbs after losing a foot or leg or antenna?

I look like a big black ant, but I'm not!

On another feeder's pole where the big ants are not a problem, the tape did its job on the smallest ants in my garden:

Those things are so tiny, but even they were able to eventually cross the tape barrier. I think the adhesive just dries out too quickly in our heat.

So I removed the tape and used some vegetable oil instead:

Hopefully that will stop the small ones, but I have no ideas on how to keep the big ones out of the other feeder.

Any more suggestions?

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