Hummingbirds
Sunbirds and honeyeaters are not the only hummingbird impersonators. “Hummingbird moths” (Hemaris) are sometimes thought to be the tiniest hummingbirds when in fact they are insects. Unlike most moths, hummingbird moths hover from flower to flower during daylight hours, causing confusion amongst observers. In flight, their wings take on the same characteristics as hummingbirds as they hover about, and their abdomens are trimmed with fanned setae (bristles), creating the look of tail feathers. (from Wikipedia) In flight, the moths tend to tuck in their legs making them difficult to spot. With close observation, one can see the antennae and leg count, clueing to the observer that the hummingbird moth is indeed just a lookalike.
Hummingbirds are found throughout the Americas and the Caribbean islands. Only 16 species breed in the United States, including the Ruby-throated hummingbird and the Rufous hummingbird. (from the Hummingbird Society) There are no known species of hummingbirds in the eastern hemisphere; however, it has been noted that similar nectar-feeding birds inhabit parts of Africa, Australia, and Asia as well as some Pacific islands. Sunbirds, found throughout Africa, India, and southeast Asia, are rich in color and contain tubular beaks that allow access to a flower’s nectaries. (from Wikipedia)
Honeyeaters, commonly found in Australia and surrounding countries, also feed on nectar in addition to insects and fruit. Honeyeaters generally hang from branches (even upside down if necessary) when feeding on nectar, but are known to hover in small bursts like their hummingbird relatives. (from Wikipedia)
South African sunbird
Indonesian Honeyeater
Right: Hummingbird moth