Today I saw a hummingbird sitting at the feeder. Something didn't seem quite right with it because it was staying still for too long and it kept shaking. A few moments later another hummingbird came up behind it and began to stab this bird in the head over and over until it fell to the ground. It appeared to be the same two birds that were fighting the other day. I was very upset and shocked at seeing this horrible attack and quickly opened the window to shoo the mean attacker away. I went outside to check on the hurt hummingbird and thankfully it was able to fly to a nearby tree, still not moving much and seemed to be a bit dazed, but at least it was alive. I removed my hummingbird feeder and won't use it anymore. It really took away all the pleasure of watching these interesting little birds. It isn't worth it for me to have a feeder if it causes the hummingbirds to be so violent with each other, in fact it feels rather selfish. I always thought that feeding the hummingbirds was a good thing, that it gave them a much needed food source, now after observing this behaviour up close, I feel very different about feeders.