Why are butterflies called butterflies?

There is some debate among experts as to how butterflies got their name. The explanation which most people believe is they got their name from a European butterfly which in one of the first that appears in the spring.

The Brimstone butterfly has a male that is bright yellow, the same color as butter. It is thought that the ancient anglo-saxon tribes that colonised England used the name "buttorfleoge" because of this and the word eventually became "butterfly".

Another explanation is that butterflies were thought to steal cream or butter. The German name for butterfly is "Schmetterling" which some experts believe comes orignially from a Czech word "Smetana" meaning "Cream".