So it's better to lift a lighter weight more often, than a heavier one just a couple of times.

No, the only thing that lifting lighter weights more often will give you is the ability to lift light things many times. That's called endurance. Lifting heavy things less often will give you the ability to lift heavy things. That's called strength. Which one is "better" for you depends on your fitness goals.

Hummingbirds only exist in the Western hemisphere. But certainly hummingbird feeders could be used for this. The feeders are usually small enough that most larger birds aren't going to be able to use them, though I do find the occasional oriole or even woodpecker on mine. An ant guard will keep other types of insects away.