Interesting... I haven't figured out what's wrong here, but I have some clues that may point you in the right direction.
First, I commented the problem code out. I set the Watch area beside the console to monitor enemy.x, enemy.y, enemy2.x and enemy2.y.
The values for enemy.x and enemy.y reported values I would expect, but the enemy2 values were both NaN. After I moved the character off to the right (increasing the loop variable), enemy2.x suddenly had a value but enemy2.y still didn't. I'm not sure why.
I added enemy2.x = 200; and enemy2.y = 200; to function background1(), and things started working in a much more expected way. The only problem was that the bee was now stuck in that position.
Sorry that I wasn't able to discover anything else. Hopefully that gets you started!