Facebook introduced Video Auto-Play back in December. This feature automatically plays (silently) while browsing your News Feed. If you click the video, it will play in full-screen mode with sound.When Facebook introduced Video Auto-play, they said there won't be any way for disable it. If you weren't interested in viewing a video, they suggested you just scroll past it. But Facebook listen to their users and added a setting to disable auto-playing videos.
Facebook Video Auto-Play is really annoying, especially on mobile devices. It can raise your phone bill, eats your data and slower your Facebook application. Many Facebook users have discovered that this feature may be responsible for unexpected charges on their mobile phone bills. But fortunately you can disable this behavior very easy.
To disable auto-play videos on your Android, you will need to access the Facebook App Settings.
Now search for Video Auto-play and set it to Off.
Voila. You won't have any problems any more :-)