Super Rats

S2, E6: Rats are the stuff of nightmares and recent archaeological evidence suggests that they once grew to massive sizes. Could these huge rodents make a comeback? Waves of huge rat sightings are sweeping our cities, and animal experts say these mutants are getting bigger - and more dangerous. Rat experts journey into the sewers and meet the witnesses who tell of cat sized rats that have appetites for anything... including human flesh.