I have two things to deter ants. One is that the feeder is hanging on 6 inches of thin nylon fishing line and also I greased the pole with soft grease.

How long is sugar water good in summertime when the feeder is basically in the shade? I think that I have only one male and it sure is slow getting used up.

I've read that in hot weather, 2-3 days is the max for leaving nectar in the feeder.

I've also read that vaseline is a good ant deterrent.

I'd be careful about greasing the pole or the hanging wire. Read someplace that if the Hummer brushes against them, they'll get the grease on their feathers and it's hard for them to clean the grease off.
I bought some ant moats from Wild Birds Unlimited that are basically the size of areasol can tops with an "s" hook on the bottom and the top. Fill it with water and hang above the feeder. Keeps ants out of my feeders (so far). Here is there web site http://www.wbu.com/ They may have a store in your vicinity. I even use the ant moats with the feeders that have built in moats. The bright red color helps to attract the little Hummers.
Or have you tried putting ant baits at the base of the feeder pole?

fritzmom....this feeder is not on a pole. I have a front porch roof overhang, and I have it hanging at the edge. I took a metal coat hanger and cut a straight length (about 10"). Then I took pliars and bent the ends up a little making a hook on each end. The way I have it hanging:

Christmas light "S" hook: (it really looks more like the figure "8") The top part of the "S" hook is hooked into one of the grooves at the end of my porch overhang.

My hanger that I made is hooked into the bottom part of the "S" hook. Hope this all makes sense.

I do have some ant traps out, but they are not in the same area as this feeder, maybe about 20 feet away and in the back yard. The ants have to get to my feeder by crawling up onto the roof. Do you think anywhere on the ground underneath the feeder would be ok for ant traps? I'm wondering if I should put one on the roof...lol.

donnas
If you have carpenter ants getting to your feeder off the roof they are probably in the house. You need to address that issue and you will eliminate the ant problem with the feeder. I think the house is more important so I would call someone in to take a look.

As far as greasing the pole goes, if the grease is a foot above the ground, the hummer is very unlikely to get in it. Also I don't see any problem with fishing line. These little hummers are very skilled. After all the frrder is going to be hung on something or other.

Donna, try moving the feeder over about five or six feet away from where it is now. I have read that the hummers will find it very easily but the ants will not. The ants will follow the chemical trail that they have left- when they get to the end of it there is nothing there for them and they give up. Good Luck and do consider getting the house inspected, carpenter ants can do terrible damage.

You know, we did have a large oak tree cut down about 2 years ago. This tree was only about 5-6 feet away from our house in the back yard. We were afraid of it possibly falling onto the house during a bad storm. The guy who cut it got as close to the ground as he could. What he couldn't get is still there. It's probably gonna cost up in the hundreds of dollars to have the stump removed. Gosh, isn't there a less expensive way to remove a stump? I know this isn't related to hummingbirds, sorry.