Several years ago we had our trailer up in Flagstaff on the edge of the national forest. They were having a drought, and when we put up a hummingbird feeder, we had dozens of hummers at our one small feeder. So we put up another, and another and yet another. We had a total of 4 feeders set in about a 25 foot circle with two hanging off the front window awning. Early in the morning we would be awakened by about 80 hungry hummers. When I would go out to fill the feeders, they would land on my head and shoulders, and when I hung up the full feeders, those that had to wait would drink from my hands. We filled the feeders two or three times a day.
We never had such a throng again. It was just a very dry year and their natural food was not available. But it was an experience we will never forget.