Where did the word, "butterfly" come from?

Dear Mr. Alice:

My mom and I were watching a butterfly and I asked her why they're called butterflies. They fly, but we couldn't figure out where the butter comes in. Can you help us? Thank you very much.,

-- Tiffany, 3rd grade

Well, you're very welcome, Tiffany. Good question. Wish I had a really good answer, but sometimes grown-ups do things and then forget why they did them. Kind of like when your mom forgets where she put her car keys. That's sort of what happened with the name "butterfly." A long, long time ago-- longer than your mom's been alive, longer even than Matthew Alice has been alive!-- somebody made up the word, a lot of people liked it, and it just stuck. Now all we can do is look around for an explanation that seems to make sense, like your mom tearing apart the house looking for those keys. Anyway, hundreds of years ago in Europe, people believed that butterflies liked to drink milk and eat butter that was left out in the kitchen. (I don't know where they got this idea.) In German, the word for butterfly is Milchdieb, "milk stealer." So, in English, I guess butterflies fly away with the butter. This is the explanation that most people think is correct.

A few people interested in word origins think the butterfly was named after a pure-yellow one, which must have looked like a flying butter pat. There's another sillier explanation that some experts believe. Butterfly poop is yellow and maybe looks like butter. I don't believe this one. I don't think you should either, Tiffany.