One day, we made a half-gallon of sugar water, and 139 hummingbirds came to drink the nectar in that day. Therefore, each hummingbird consumed 0.46 oz. of nectar. There was 64 oz. of sugar water in the feeder. If we divide 139 by 64, we get 0.46 (the amount of nectar consumed by each hummingbird). However, this is not rocket science; it's sometimes a matter of fun to do this kind of calculation.