In the last level go into the command tower...but be carefull of enemies, ok then you up the door on the left (at the very top), search the outer wall of the level (you should see AA guns), one of the guys is over 1000 yars away, Goodluck hitting him! I got about a 1006 yard head shot on him, see whaty ou can get
Enter "RATBOMB" as a profile name and when you shoot any rat they will explode and will destroy even a tank if it is close to the rat. The exploding rat will also kill soldiers who are close enough. Be warned you can also die if an enemy shoots a rat that is by you.