Poltergeists:

[Chronos]

The word "poltergeists" means "noisy ghosts" in German. From the German polter = noisy, and geist = ghost. It is the disturbances that differentiate the poltergeist from other ghost reports. According to studies, there are several forms of traces. The most common type is in the form of noises. They could be rapping and spontaneous noises. Another form would be apparitions such as black shapes or ghostly appearances. Sometimes apports had been reported in cases. The spontaneous manifestation of objects (e.g., small stones falling on house roofs) without apparent source. There are also documented cases that reported levitations. People had been lifted into the air without any aid. Reports had also shown moving objects in cases when items moved by themselves and spontaneously. Occasionally, people had been attacked by the poltergeist. Scratches and bites are common skin markings. Others phenomena include both small fires and leaking of water.
 Poltergeist activities tend to strengthen and then diminish. It usually started with some noises first and consequently come in with some of the characteristics listed above. Sometimes the activities could be extremely disturbing to both the individuals affected and the family.
 There is no consensus as to the origins of poltergeists. The researchers are divided between those who believe poltergeists are a form of PK energy released and those who believe they are entities. Last but not least, there are researchers who believe that they are a combination of two - entities that were "allowed in" by certain states of mind.