Keeping Ants Away From Bird Feeder
I use bugsnub products. I have been happy with their ant guards for years now.
Vaseline To Keep Ants Out of Hummingbird Feeders
I tried vaseline years ago and it melts at body temperature, so it ran off and made a mess. Ants still got to my feeder. Luckily I found an alternative called bugsnub. This really worked for me.