Natural foods (pollen, nectar, and small flying insects) are becoming available, but your local hummingbirds might still appreciate some fresh nectar. Mix 4 parts boiling water to 1 part white sugar, cool, and put out in small, fresh batches after cleaning your feeder (brush, vinegar, rinse) every few days. Hummingbirds can be killed by fungus and mold that grows in the sugar-water at higher outdoor temperatures, so it is important to only put out small batches and keep cleaning and thoroughly rinsing your feeders between batches.