Those of us who enjoy attracting hummingbirds have probably witnessed what I’ll call "hummingbird wars.” There is always one hummingbird that thinks the feeder is theirs and tries their best to drive the other birds away. This is because hummingbirds are so extremely territorial and aggressive. The information below should help you with this problem.
The best way to prevent a single hummingbird from monopolizing your feeder is to have multiple feeders and place them out of view of each other around your backyard. Or you can group a bunch of feeders together so no one individual hummingbird can possibly defend them all.
You can also place your nectar feeders at varying heights. The different hummingbird species will favor and defend different hummingbird feeders that are at varying heights. Some hummingbird species like to feed at heights of 12 to 15 feet, while others typically feed on low growing flowers and will prefer feeders placed closer to the ground. Placing your feeders in at least 3 different heights will help to reduce aggression between hummingbirds.