Because she had no arms. "knock knock" "whose there?" "not sally!"
Gloves. Just kidding, he hasn't opened it yet.
A Speech Impediment :)
It's a fish.
Because he couldn't see that well!
Anxiety in 3...2...1... knock, knock *sigh* "WAIT A SECOND!" *mumbles* "I need to find pants."
giANT!!
He had no arms. Sorry that joke was stupid, let me try again. Knock Knock "Whose there?" Not Billy
She had no arms. BONUS JOKE: Knock Knock. Who's there Not Sally.