Half bee._width

Well, the problem is we are adding the entire width of the bee movieClip to the stage width, but the x point is in the middle of the bee. Therefore, we are getting about a bee-and-a-half off the stage before the conditional statement is met. Look at the illustration below:

Well, that's an easy fix.... we only want half of the bee's width added to the stage width, so the condition is met exactly when the back half of the bee leaves the stage. Just divide by two:

Great... do the same thing with the negative bee width when the condition is met and the x position is reset:

That was an easy fix: