The hummingbirds have been especially aggressive this year. They dive bomb me when I go outside if the feeders are low in sugar water. Funniest...they tease my 2 cats mercilessly! They hover in front of them on the other side of the window glass, and I swear they are laughing at them. It drives the kitties nuts, and I learned a valuable lesson from those hummers....if you really want to get back at your adversaries, just laugh. Be happy. It drives them wacko!