I know a little about hummers. The food is a 4 parts water to 1 part sugar (by volume) mixture that can be filled in the feeders and is usually ok for about 4 days, then it begins to ferment (yes you can get your hummers hammered) SO watch it!!
As far as bats, you could leave do incantations. or build a barn, we have a bunch that live in our barn and I never can see where they are during the day.