An expert reveals the hidden meanings behind emojis that parents should look out for - including the cat face, dynamite and ...

When Higgins tweeted Tuesday night for the first time in two weeks, it was just an emoji of a blue cap. What did it mean? Nobody knew, but the tweet had more than 500 replies within 20 minutes.

Sometimes words just aren't enough to convey what you have to say. Emoji has been around since 1999, but these winky faces and seemingly random characters have only fairly recently caught on.