There may be times such as during an Open House or Parent Teacher Conferences where you want a particular YouTube video to loop. YouTube, of course, does not natively do this but there are some tools that can make it so.
One such tool is an app called Looper for YouTube and another is an extension called Looper for YouTube. The app takes you to youtubeloop.net and allows you to insert a YouTube link to play the video on a new page that loops. The extension, on the other hand, allows you to loop any video on YouTube itself. I personally like the extension better but both tools work well.