SCP-1104

**Item #:** SCP-1104

**Object Class:** Keter

**Special Containment Procedures:** Complete destruction
 of SCP-1104 is endorsed, should adequate means be developed.  While
individual instances of SCP-1104 are easily terminated, SCP-1104 is
endemic to subsurface geological formations in northwestern ████████,
rendering the (surmised) primary population of SCP-1104 inaccessible to
convenient lethal agents.  A surrounding area 10km in diameter has been
designated Site-104 and cordoned from the public under guise of
endangered species preservation.  Personnel must wear N100 air
filtration masks while within Site-104.  Mammalian organisms exceeding
10kg (other than authorized Foundation personnel) entering Site-104
should be assumed contaminated and incinerated at facilities on-site.

**Description:** SCP-1104 is a species tentatively
identified as a member of order Chelicerata.  The life cycle of SCP-1104
 comprises at least two distinct phases, the first being a larval stage
approximately 0.4mm in diameter.  At irregular intervals, larval
SCP-1104 are expelled from lava tubes within Site-104 at concentrations
up to 200 individuals per cubic meter.  These remain airborne for as
long as 14 hours and have been documented to travel at least ██ km under
 favorable weather conditions.

When inhaled, larvae will adhere to nasal mucosa, where they excrete
an array of H1 receptor antagonists that suppress both local
inflammation and implantation of further larvae.  Over a period of 6-8
months SCP-1104 will grow and extend appendages through the host's
ethmoidal canals.  Hosts generally remain unaware of the presence of
SCP-1104, apart from persistent but non-specific headaches.  On
maturation, SCP-1104 will begin applying pressure to the host's optic
nerves causing obstruction of the central visual field.  This pressure
is applied selectively when the host is not oriented toward the local
gradient of atmospheric hydrogen sulfide, which SCP-1104 can detect
through the host's inhalations.  After an initial period of distress,
the host will begin to prefer to face and travel in the directions where
 they do not experience visual disturbances, thus tracing the source of
hydrogen sulfide.  Upon reaching a zone of sufficient hydrogen sulfide
concentration, SCP-1104 projects appendages into the host's prefrontal
cortex, causing unconsciousness during which SCP-1104 exits the host via
 the ocular cavity.  After leaving a host, SCP-1104 attempts to locate
and enter the source of hydrogen sulfide, such as a lava tube or sewer
pipe.  SCP-1104's subterranean lifecycle has not been documented.

Although humans display the same instinctual aversion as any animal to
visual disturbances caused by SCP-1104, the behavioral response is not a
 compulsion, and hosts may defy the influence especially if informed of
the nature of SCP-1104 (Note that subsequent hostility toward research
personnel should be anticipated).  Attempts at surgically removing or
poisoning a fully developed SCP-1104 result in immediate elicitation of
its exit response.  Post-exit hosts exhibit complete aspontaneity due to
 orbitofrontal lesions, and to date have provided no pertinent
information in debriefing.