Don't use anything BUT white sugar, boil the mixture and let it cool.
During hot weather, change the it often.
Clean the feeder well but make sure you rinse and rinse and rinse and then rinse some more.
If you get ants, slather some cooking oil on the hanger well above the feeder.
Why do you need to boil the mixture?
One reason is that it makes it easier to get the sugar into a solution. Some say it stops or slows the fermentation process but I don't think that's true because that is caused by the birds themselves. That always seemed strange to me but there you are.
Some years ago, the Arizona Sonora Desert Museum found that birds were dying from other reasons than just the red food color that we all now know is dangerous. They found that boiling stopped the deaths of birds in their own enclosure.
Another point is that hummers don't live on flowers or nectar. They are insect eaters first and the nectar is a source of quick energy.
If you find a hummer, try warming him in your hand and if he's comes to, offer the nectar, preferably by 1cc syringe.
I have rehabbed hummers, including tiny chicks in their nest. I've actually had people cut off the entire branch the nest is on and, believing the parents have deserted it, bring it in with the chicks in the next. Maddening, to say the least because the parents have not deserted the nest. They're nearby, watching.
Anyway, hand raising tiny hummers is just incredible. There is special nectar that is a complete food, very expensive but without it, they would die.
