Probic vent

The probic vent was an essential part of all cloned Sontarans.

Information
At least partially artificial, the probic vent took the form of a small metallic tube attached to the back of the Sontaran's necks. This vent was normally used by the Sontarans as a way of directly feeding off energy to "recharge" rather than eating (as the latter was slower). Raw plasma was fed directly into the vent to nourish them. (DWM: The Betrothal of Sontar)

The vent was also a major weakness, since a blow to the probic vent could knock a Sontaran unconscious or even kill them. (DW: The Time Warrior) A lesser blow could cause them pain and/or stun them. (DW: The Sontaran Stratagem) An arrow (DW: The Time Warrior) or a thrown knife (DW: The Invasion of Time) would almost certainly prove deadly.



The Sontarans did not find it a problem, however, since it meant that they must always face their enemy in battle and could not be cowardly and run away. (DW: The Time Warrior, The Sontaran Experiment)

However, some people occasionally found ways to disable Sontarans from in front of them. For example, the Doctor momentarily disabled General Staal using a squash racquet and a ball by rebounding the ball from Staal's teleport pod and onto Staal's probic vent. (DW: The Sontaran Stratagem) Donna Noble used a hammer to hit a Sontaran on the probic vent when it had its back turned. (DW: The Poison Sky)

The Doctor used the same hammer in the year 2010 to stun a clone of Commander Skorr who was about to shoot Mickey Smith and Martha Jones who were working as freelance alien hunters at the time. (DW: The End of Time)

The placement of the vent may have been deliberate, as it would force the Sontarans to face their enemies.

List of weapons used to strike a probic vent

 * A metal pole (DW: The Time Warrior)
 * A bow and arrow (DW: The Time Warrior)
 * A knife (DW: The Invasion of Time)
 * A squash ball (DW: The Sontaran Stratagem)
 * A hammer (DW: The Poison Sky)
 * A high-heeled shoe (SJA: The Last Sontaran)