It started happening when Apple's operating system, iOS 8.3 came out.
By tapping and holding on a chosen emoji, iPhone users of iOS 8.3 or above are now given the choice between five different skin tones and new flags.
Apple users who are still using iOS 8.2 and below are not able to see the new emojis.
Instead they are replaced with a picture of an alien face inside a black square, next to the original emoji.
Apple wouldn't give us a comment on this, but on their website it says: "If you get a message with unexpected characters instead of emoji, try updating your iPhone, iPad, iPod touch or Mac."
If you're viewing the new iOS emojis on devices other than Apple they can appear as lots of other things, like blank spaces, boxes, equal signs, question marks, or even line breaks.
Have you noticed any of these little guys creeping into your texts and social media, when you know they weren't intended to be there.