Bodies repelling dust

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I have a slightly silly question, but not having much of a hard science background myself I am at a loss to explain this phenomenon: I was sitting in my room after doing some cleaning today and a shaft of light was coming in the window, illuminating all the particles of dust I'd kicked up. I stuck out my finger and tried to catch one of them on it, but every time a particle came near, without me even moving, it seemed to be repelled away. As soon as it came within about 3/4 of an inch of my finger, it would appear to hover for a moment and then actually accellerate upward. If I followed it with my finger, unless I moved very quickly, it would always maintain a distance of at least 3/4 of an inch from me. So ok, it seem that my body is exherting some force on the particle without me even touching it. My question is what? Thanks for anyone who can shed some light on this.