Facebook inbox notifications pop up on my screen even when I don't have facebook open?

[workaholic]

Hey guys,
I know the title's not very clear but it was hard to summarize well.

Basically, I'm always logged into facebook on my laptop (Macbook pro, idk if this is just an annoying apple thing...), and when I get a facebook message (inbox), it shows up on the top right hand corner of my screen, even if the facebook tab is closed etc....
How do I get rid of this?
I know I could just log out of facebook, but that's just inconvenient haha...this only started happening about a week ago.
So when I get a new message, in the top right hand corner, a little rectangle comes down, saying "....... sent you a message" and then displaying the first line or so, of the message...it's annoying, especially if I'm in class etc, and that just comes up..

someone please help me, I've tried looking at the notifications/settings thing on facebook and can't work it out!

[pri✍]

Maybe you put bookmark on Facebook message on your home screen? You should investigate what are the things you put on your home screen.