His eyes start to stream and he can’t stop sneezing.
A man knows there’s a cat inside a closed cardboard box, even though he can’t see it, hear it or smell it. How?
Give me a hintThe hint
His body works it out before he does.
Reveal the answerHide the answer
He’s allergic to cats
Source: Eric Stephan, in Jed Hartman’s list of situation puzzles, no. 1.18