These are a common sight in the skies of most countries, and there are few circumstances where misinterpretation as a UAP is plausible. However, this can, and has, occurred. Some birds have highly reflective undersurfaces and in bright sunlight can, if they are very high, appear as white shiny ovals or discs which may occasionally appear to “flicker” or “flash” on occasion. Similarly, at night time it has been known for street-lighting to be reflected from their underbellies – giving a characteristic colour (orange/yellow in areas of sodium lighting and blue/green in areas of mercury vapour systems).

Telltale signs: Usually a formation of objects, random “milling” around motions (as
with birds in flight), flickering of light output (as wings flap or reflected light varies).