[pale-hands]

You would expect closely related languages to have similar words for a common animal, i.e. to be at least somewhat conserved. I do find it mysterious. Another one: Dutch vlinder, Afrikaans (very close descendant) schoenlapper.

I think the papillon dog breed has big, butterfly-like ears!

[stevula]

But the main reason closely related languages tend to have similar words is because the word existed before the languages diverged. When the already distinct languages borrow a word independently, the word might have a different story or source behind it.