Update

Natural Nectar
Ruby-throated hummingbirds can be found in many habitats, from forest to streamside. Whatever habitat, they always need nectar or another very sweet liquid. In early spring they find it at sapsucker drill holes--otherwise they are virtually always found near flowering plants, or sugar-water feeders. By flying from flower to flower, the hummingbird pollinates the plants it feeds on. Some plants can only reproduce because of hummingbird pollination.

Photo: Dennis Church CC BY-NC-ND 2.0
hanging the feeder outside the classroom