Similarly, if you ask it something that requires human knowledge to answer, even child like human knowledge, chatbot's don't ever have good answers. For example, I ask:

   If I drop a pencil, what will happen?

A valid human like response could be:

    - Um... it falls?
    - It bounces on it's rubber tip
    - It drops

Each of those answers require a pretty basic level of human knowledge, but I've yet to see a chatbot that gives anywhere close to a good answer.

Eugene Goostman replies:

    I have to think about that some more :-)) Was that a fruitful conversation?

Cleverbot replies:

    I didn't say you don't have a head.

Neither are things a human would ever respond with, but the question is a totally normal question (if odd).