For the past several months, I have noticed my hummingbird feeders were empty in the morning. I attributed this is leas but could not find th leak and switching feeders around did not help. The feeder in the front of the house seemed to be the one that leaked but switching did not help.
Then I discovered the cause. bats were eating the nectar.
The Mexican long tongue bat, to be specific.
Here is a video of them feeding.
I got up at 3:30 to watch them and some had one foot wing spreads.
By day, the MLTB roosts in caves, mines, and buildings, often clinging by one foot near the roost entrance. Single young are born to female bats in June and July. These maternal roosts are usually in Mexico. Both species follow a migratory nectar corridor of cactus and agave blooms briefly entering the United States. They are present in the United States during the summer months. By late summer, they migrate south into Mexico and northern Central America by winter.
The main portion of the diet for nectar bats is nectar along with the protein and lipid-rich pollen, which they lick and groom off their fur. During the summer when cactus fruits are ripe, they will also gorge themselves on the fresh fruits of cacti. They may also take some insects to supplement their diets.
So, the mystery is solved and probably will be temporary until fall.