This morning the hallways of the Mix studio were filled with a couple of kids laughing, Grant and Katie. Their laughter was contagious and quite cute and all off a sudden Katie busted out a knock knock joke. I'm guessing she was about 4 and said, "Knock Knock." One of the other jocks in the building replied to her with the traditional "Who's there?" And Katie replied with apple.

"Apple who," the jock said.

"Apple head ," and she just started laughing uncontrollably and was quite hilarious and then said, "OK, your turn!"

The jock then said, "Knock Knock."

Katie says, "Who's there?"

"Boo," he says.

"Boo who?" Katie replies.

"I'm sorry I didn't mean to make you cry," he said!

Katie and Grant both start laughing again!

It was something cute and a great way to start off a Monday, with the sound of children laughing.

With that uplifting story of the morning, I'm curious, what is your best knock knock joke? Tell it to me in the comment section below!