Well, maybe not as bad as the blue tile or the brown stick, but here goes:

There is a daddy camel and a little boy camel. One day, the little boy turns and asks his daddy, "Daddy, why do we have such long eyelashes?"

The dad replies, "Well son, its to keep out the sand from our eyes when there is a sandstorm."

The little camel thinks about it and then says, "Daddy, why do we have such big feet?"

The dad replies "Well son, its to stop us from sinking into the sand." The little camel thinks about this, and then says "Daddy, why do we have humps?"

The dad replies "Well son, its because we can go for miles without finding any water so we keep a store in our humps."

The little camel thinks about this, then eventually says, "But dad, we are in Edinburgh Zoo!"