Articles relating to poltergeists (German for "rumbling ghost" or "noisy spirit"), a type of ghost or spirit that is responsible for physical disturbances, such as loud noises and objects being moved or destroyed. Most claims or fictional descriptions of poltergeists show them as being capable of pinching, biting, hitting, and tripping people. They are also depicted as capable of the movement or levitation of objects such as furniture and cutlery, or noises such as knocking on doors. Foul smells are also associated with poltergeist occurrences, as well as spontaneous fires and different electrical issues such as flickering lights. Parapsychologists Nandor Fodor and William G. Roll suggested that poltergeist activity can be explained by psychokinesis.