In its comparison of butterflies and moths, the Encyclopedia Americana states: "There is no single prominent aspect of their morphology or ecology which suffices to distinguish between them." However, "the moths form the greater part of the Lepidoptera, yet the species most familiar to man are some of the more colorful diurnal (dayflying) butterflies."
《大美百科全書》在蝶與蛾的比較上寫著：「兩者在型態與生態上並無非常明顯的項目可做分別。」只不過，「蛾類佔了鱗翅目的大部份，但是較為人所熟悉的卻是一些亮麗的日行性蝴蝶」。