It was around the time turned six years old, shortly after the assassination of President Kennedy in 1963. We lived in Monterey Park, California. I could not sleep one night, so I went to the kitchen and stood with my back against the breakfast area wall. I did not turn on the light, but I could see fairly well into the living room. I'm sure it was well past midnight, and I know for a fact I was not dreaming, because my dreams have always been surrealistic or everything displaced.
What I saw next shocked me so much I could not move or scream. About six little, 3- or 4-inch-tall human-like beings came out of the gas floor heater and walked around the the far side of the living room. They were not wearing clothes, but they were not naked either. I saw no genitals, but rather, a not-so-smooth skin or jump suit. They all were carrying small, but in proportion to them, long-handled sledge hammers. Two or three of these little humanoids walked up to me and started hitting my toes with the hammers. I felt the hits that were like painless, light tapping throbs.
After a few minutes of this harmless attack on my feet, a larger -- maybe 18 inches tall -- little man of the same type emerged from the floor heater grid and walked around, never getting close to me, in a grouching manner for a few minutes. Then with no sounds, or signals to each other, they all retreated back down the floor heater grid, and I turned the lights on and ran past the the opening in the floor to my bedroom without waking anyone in the house up.
These creatures never came back. This was the biggest event of many strange happenings in the house, and not only experienced by me, but my older sisters as well. I have heard stories like this happening to other children, too.