Those smiling faces are merely the technique that snowball fiends use to gain entry into nice, dry, warm houses!
Once the flurry of snowballs and giggles are released the fiends will run back off into the snowy day, leaving you mopping up the floor until their next attack.
But the worst part is that they unleash such a blast of snowy day cheer with each volley that their giggles become contagious and the serious-stop-throwing-snow-in-the-house voice can’t seem to make an appearance because you are too busy throwing the mopped up snow back at them.
On second thought, open the door.
Every house needs a little snowy day cheer!