In which a sparrow is a clinging bird
Technically speaking, sparrows are supposed to be perching birds, unable to do the stunts that clinging birds can do. But they're smart little buggers. The sparrows in my yard are entirely capable of learning how to cling upside-down to a suet feeder. They aren't as good at it as the woodpeckers, but they are plenty good enough to get the food. That counts.