Vent scrit

s were an alien species of rodents with bucked teeth. They were larger than rats.

Vent scrits lived in every spaceship. They came to Cardiff with the Sorvix. Jack Harkness considered them to be a more efficient invasion force than the Sorvix, Sontarans or Daleks.

Some of the vent scrits were infected by an alien sexual parasite that eventually was passed onto humans.

Torchwood Three eradicated their population to prevent the disease from spreading. (AUDIO: Love Rat)