A few years ago, I was staying at my mother's house for about a week. She was standing in the kitchen, facing the direction of the living room, looking at me. I was standing in the living room, facing the direction of the kitchen, looking at her. We were about two feet apart, I'd estimate. This occurred at about 2 PM. The shades were closed. The kitchen light was on. We were the only two people in the house at the time.

I didn't see this happen, but my mother claims that she saw a small black shadow–about three and a half to four feet tall (she measured in relation to my height)–appear behind me and sort of peek around my shoulder. When my mother looked directly at the shadow, the shadow darted down the hallway toward the back bedrooms and disappeared. The whole incident lasted maybe four to five seconds.

My mother and I have seen things before, but most of the time we can explain our experiences away – drowsiness, external factors, etc. For example, in her house, I saw a black shadow close the guest bedroom door once, but I was taking a nap and the window was open, so my brain probably just created the image of a black shadow to explain the fact that the door was closing, almost certainly due to the wind. In this case, though, she saw this in the middle of the afternoon. She hadn't been sleeping. She wasn't on medication. We were alone in the house. Shades closed, no shadows being cast. (Even if a shadow had been cast by a nearby neighbor, no windows face the hallway.) Neither of us was moving at the time.

I would like to find a non-paranormal explanation for this event, but I am struggling.