I did it at the post office too much and it messed up my sleep patterns.
Or you can go into options and see what key it's mapped to.
If you don't want to take eight seconds and would rather click around trying to find out...
Try the usual suspects. Middle mouse, G for "grenade".
Probably one of those two.
I can kind of grow a creepy pedophile mustache.
[Edited by Dhampy, 6/2/2013 11:26:30 PM]