1 Answer

 1)  You coud buy a feeder with Ant,s and Bees  guard. Some feeders come with plastic mesh bee guards. Some feeders will also be prone to  dripping, which will undermind the effectivenss of the bee guards

 2). Try moving the feeder, a few feet  and trick the Ants into thinking thats it gone and they wont find it, If they do find it , take the feeder down  for a day or two, until they stop looking for it. The Humming Birds wont give up as easy as the ants. Once you hang up the feeder, the H. Birds will find it again.

3) You could give the ants their own feeder, like the H. Birds feeder Ants, bees are attracted to higher  concentration of sugar, so in ants feeder use a nector ratio  of one part sugar and three parts water. In the H.Bird feeder instead of using the standard 1 to 4 ratio use a ratio of 1 to 5 parts water. This ratio not as sweet as 1 to 4,but will be still good for the H.Birds.

4). You could buy a basin or saucer-type H.Bird feeder These feeders are pretty much drip proof, so they not as likely to attract insects in first pace. Also nector level will be lower and out of reach of insects, but not out of the H.Birds reach with their long tongues.

      Hope you will get some ideas from above.