This happened to me right around before I graduated from grade school.  I decided to walk upstairs one night to ask my sister something. Since our parents were out the house was still and most of the lights were off. Her upstairs bedroom was at the end of a short hallway leading from the living room - it was about 9:00 PM.

I remember ascending the steps in the dim yellow light from our stained glass light fixture hanging overhead and the distant ticking of a clock. As I rounded the top of the stairs and started down the dark hallway toward my sisters room something very hostile made its presence known to me. From somewhere that I could not see came a threatning jolt of a noise that sent me running back to my room at top speed without looking back. I will never forget the sound.. if I had to attribute it to anything it sounded vaguely like a cornered animal but considering we had no pets I can't explain it. It was a fleshy rattling hissing gurgley grunting sound that made my heart burst out of my chest and my limbs rubbery from the adrenaline - probably the scariest waking moment of my life!

I live in an old house" built 1912", on the edge of a small town, next to a river. So I have Bats in the attic, Squirrles in the walls, and Ground Hogs in the basement. You would be surprised the sounds My family have heard over the years! I would say "Dont Panic!" till you see some thing. Then shot it! "Eatting it is Optional!"

Bomber, I can totally appreciate the notion that it was some random demented nocturnal animal that popped out from behind a picture hanging on the wall, scared the pants off of me then disappeared without a trace.. but in all honesty the chances it was an animal are in the millions. I'll try to prove why.

The house is a three-level duplex built in 1977 in Southern Ontario, the opposite side was occupied at the time. We never had problems with any kind of animals getting in, nor did any of our neighbors. The house had never had any problems with the roof having holes. All the windows of the house were always shut completely or left open a crack with the screen shut and locked. There is no fireplace / chimney in the house.

When I attributed the sound I heard to vaguely resembling an animal here's what I meant  - What I heard was too bizarre and harsh to have come from a human. The only other logical deduction is that either a large animal somehow got into the house only to make an unearthly threatning sound at me then disappear - or that it was something supernatural.

I see.  Completly differant enviorment from me then.  If  supernatural, who knows. I have nothing to compare it with.  Weird!