From NASA Science News:
Fire is inanimate, yet anyone staring into a flame could be excused for thinking otherwise: Fire dances and swirls. It reproduces, consumes matter, and produces waste. It adapts to its environment. It needs oxygen to survive.In short, fire is uncannily lifelike. Nowhere is this more true than onboard a spaceship. Unlike flames on Earth, which have a tear-drop shape caused by buoyant air rising in a gravitational field, flames in space curl themselves into tiny balls. Untethered by gravity, they flit around as if they have minds of their own. More than one astronaut conducting experiments for researchers on Earth below has been struck by the way flameballs roam their test chambers in a lifelike search for oxygen and fuel.