|Home time period||Early Pleistocene to Present|
|Appearances|| Episode 1.2|
Rats are medium-sized, long-tailed rodents, a number of which live in sewers and underground tunnels.
Helen Cutter noted that three quarters of all mammal species living on earth right now are rats and bats, so it is likely that they would be among the dominant species in the Future. In the original future timeline, bats evolved into Future Predators. (Episode 1.6), but it is also possible that they evolved from a species of rat that gained echolocation. However, history was changed so the Predators were artificially created. (Episode 3.3, Episode 3.9)
A similar thing happened when a baby Kaprosuchus came through an anomaly into a house. After being flushed down the toilet by the house's resident, it ended up in the sewers where it ate a nearby rat. (Episode 4.2)