I have observed our hummers absent for a few days as the days become warmer then all of a sudden show up to feed at their feeder. We were very fortunate to have a mama hummer build a nest on our patio fan this spring. Watching the two baby hummers grow and to be present when they fledged was awesome. Lately, I find them at the feeder early in the morning before the sun . Here's a pic of the two babies before they fledged.