Three Dirty Kids Just Knocked On My Door Singing Christmas Songs

A little while ago the doorbell rang, I looked to see whose vehicle was here and I didn't see any. I had to look out another winder closer to the door to see who it was.. It was three kids, two girls and a boy.. They girls looked to be around 7 or 8 and the boy.. maybe 10ish.. They looked dirty. As in the little girls hair wasn't brush well, if at all. The two girls were white and the boy appeared to be latino (specifically mexican).

Anyway, I have two dogs inside and they run right to the door when someone rings the doorbell or knocks on the door so if I would have opened the door up all they way they would have run out so I barely opened the door and asked if I could help them. They started singing "we wish you a merry christmas. we wish you a merry christmas" and I was about to just shut the door in the middle of them singing, but I thought "these are kids, don't be an a-hole" so after they finished they sort of looked at me like they wanted me to give them something, but I just said "you to" and closed the door.

For some reason the first thought that popped in my mind was "I bet their parents put them up to this. They dropped them off and told them to go knock on doors, sing them a christmas song and wait for them to give you something". This ever happened to anyone?