Fecund and secretive, rats are omnivorous rodents that particularly thrive in urban areas. Sewers, abandoned buildings and underground caverns are all common burrows for rats. Generally rats are not aggressive and will quickly flee when confronted with a much larger creature, such as a human. Rats do form swarms to devour food, but they only scavenge carrion, not hunt it. When swarms of rats form it is almost entirely to blame on dark sorcery and magic, though the ambient evil of a place can lead them to become far more aggressive than they are naturally.
Rats are typically distinguished from mice by their size, being the bigger of the two; though large mice and small rats are often confused with the other.Wild rodents, including rats, can carry many different zoonotic pathogens; most commonly filth fever. The fact that they are carriers of such deadly diseases can make them far more dangerous than their small size would make them seem.