A person can use their body to know if a ghost is present. Ghosts are documented to be cold entities. Thus, the body would react by forming goosebumps when the ghost passes. A person can use this cold sensation to find ghosts. Blows of cold air could also signal a ghost walking alongside the hunter. This blast of cold air is a better indicator if the air is still and at room temperature, because science cannot explain how cold air occurs in a room with warm, still air. Another sense that could be used would be smell. Some ghosts create a scent when a person passes by the ghosts. It is said that the smells of ghosts are remnants of the smell that ghosts had when they were alive. Science can't explain how a person can smell cigarette smoke when they don't smell it.