Knock-Knock! Who's there? Bring a smile to your children's faces with the 101 Lunchbox Notes with Knock-Knock Jokes for Kids. Each colorful tear-off notes has a blank space on the back for an encouraging message. Use the notes to write words of encouragement, or as reminders of activities or tasks, or just to brighten their day! These little notes are a fun way to show your children that you care about what happens in their days away from you.