Many things are named for obvious reasons. In example, an orange was called an orange because of its color. Butterflies could be called butterflies because of a couple of different reasons...

1.) The word “butterfly” has been around for a long time. One thought about where it's name may have come from is the theory that the name was supposed to be“flutter-by,” because of the way they flutter by... If that is truly the case, then somewhere along the way their name has been switched around to butterfly.

2.) A false etymology claims that the word butterfly came from a Spoonerism of “flutterby”; however, the Old English word was buttorfleoge and a similar word occurs in Dutch, apparently because butterflies were thought to be witches in disguise who stole milk and butter at night.

3.) An alternative folk etymology, current in Great Britain, is that the name originated as a contraction of term butter-coloured fly referring to the Brimstone Butterfly, Gonepteryx rhamni, often the first butterfly of Spring.