DON'T OPEN YOUR EYES
On the last day of every month, close the blinds or curtains before you sleep. If in the middle of the night, you hear a tapping noise at your window, don't open your eyes.
If you're one of the unlucky ones, you'll hear that pebble sound at your window. It's not a friend, just keep your eyes shut. The sound will get louder, the tapping will get faster and faster. Don't let your curiousity get the better of you; don't move. It'll lose its patience, it'll start thumping the window. Your window will shake and shudder and the noises will only get louder. It will furiously pound the window and shake the panes; don't worry, the window won't break for goodness' sake, DON'T OPEN YOUR EYES. No matter how scared you are, no matter how badly you want to scream, pretend like you don't hear, pretend you're still asleep.
After a while, the noises will stop. Don't fall for it, keep your eyes shut. Try to sleep if you can. Don't get up, don't open your eyes, until the sun comes up.
Those who do open their eyes... well, no one really knows what happens.
Pitaya*