item #: SCP-XXXX - KNOCK
Object Class: Euclid Keter
Special Containment Procedures Currently, a single SCP-XXXX has been contained within its 4 x 4x 4 meter testing cell in site ██. No one is permitted access to SCP-XXXX's cell without written orders from Level 3 personnel. The entrance is to remain locked at all times. Microphones and recording equipment have also been built into the walls of the containment cell. Maintenance personnel are permitted to perform necessary repairs on the equipment.
If personnel hears a knocking on any of the doors throughout the facility, they are to report it immediately. Do not open the door under any circumstances. Personnel will be sent to assist you.
Object Description SCP-XXXX is a designation given to a an unknown number of phenomenon which share the same anomalous behaviour. SCP-XXXX manifests itself as a repetitive knocking sound, which can be heard on doors, windows or other closed apertures. The source of this knocking is currently unknown, though it is speculated that the knocking demonstrates the presence of an intelligent life form. If true, said life form is invisible, intangible and unresponsive to any attempt at communication.
Experimentation has revealed that SCP-XXXX gravitates towards human subjects; if given a choice SCP-XXXX will always knock on a door closest to a person. If the door is opened, SCP-XXXX will momentarily cease knocking on that door, and begin knocking on the next one it encounters between that and the nearest person. From the distance and time covered between knockings, the SCP-XXXX's maximum speed has been calculated at 2.23 meters per second.
If SCP-XXXX is permitted access to a human subject, SCP-XXXX will target that specific subject until [EXPUNGED]. If multiple human's are present, SCP-XXXX will pursue them simultaneously, knocking on multiple doors at once.
As already mentioned, there are a lot of these things going about unseen and unsecured. Who knows how many there are, attempting to gain access to restricted areas. We can't allow the risk to on site security. A method to capture or destroy them is vital. I'm upgrading to Keter. -Dr. ██████████