Looking for a horror movie's title?

I would like to know if any of you saw a movie with ugly little creatures that prey'd on peoples blood. It was an older horror movie made Id say around the 60's 70's or 80's. All I can clearly remember is that at the end of the movie just when you thought the creatures were rid of, this huge one (I presume the mother) rises out of this what looked like a broken down backyard or maybe a junkyard and opens it's mouth showing razor sharp teeth, and then something like a "?" or "the end ?" appears on the screen, then the credits roll. The little creatures in the movie were dark, and I dont think they had fur. I can tell you Its not critters, or gremlins, or even ghouls. if anyone can remember this movie please do give me the title of the movie. Thanks