Reuseable Cage and Nesting materials. Hang cage so that Hummingbirds and other birds can easily find the nesting materials they need. Large 1.5″ grid surface area allows bird to grab materials easily and helps materials dry out faster. Allows a few Hummingbirds to build a nest at the same time. Hummer Helper takes the place of lichen in lining the tiny nests. Other birds such as Goldfinches and Titmice will also appreciate it.