Here's why:
* Grammatically incorrect: The sentence doesn't make grammatical sense. It's missing words and doesn't have a clear subject or verb.
* Lack of logic: There is no logical connection between flies and elephants.
* Potential for a pun: The phrase "can than" could be a mispronunciation of "can't stand." This could lead to a joke about elephants being too large for flies to stand on.
If you're looking for a real question or statement, please clarify what you meant.