Plains rat

The Plains rat is a rodent native to Opal territory. Responsible for the abandonment of Hira and its transformation into the so-called 'City of the Rats', the Plains rat are known for their voracious appetite and ability to spreads disease.

History
The rat plague in Hira seems to have begun at some point during the reign of King Brandon and reached its peak during the reign of King Lucan, though neither king was aware of the severity of the situation and offered little help. The people of Hira were driven into a panic by the rodents and lost faith in the city's leaders; instead, the rat catchers were looked to for leadership.

Secrets of Deltora
Doran wrote of the plague in his journal. He advised travellers to avoid Hira at all costs because of the rats, and suspected that the city would soon become abandoned.

The Deltora Book of Monsters
Josef wrote about Plains rats and their overtaking of the city of Hira in his book, The Deltora Book of Monsters. He touched upon how a canal was dug into the Broad River in an attempt to contain the rats within the lands surrounding Hira. After talking to Steven the peddler, Josef also learned that the rats were merely food for the great serpent, Reeah.

City of the Rats
A hoard of rats streamed from the ruins of Hira and attacked Lief, Barda and Jasmine when they crossed the Broad River. They were able to keep the rats at bay with fire beads until dawn.

Upon entering the ruins, the companions encountered thousands of rats wherever they went. They were able to keep them at bay thanks to the pipe that blew bubbles of light they received from Tom, and because their garments were covered in Scarlet Night fungus. After the death of Reeah, the rats feasted on the giant snake's body.

The Sister of the South
Hira was abandoned when the grey tide awoke. Most of the rats fled into the river, where they swiftly drowned. One particular rat tried to eat the grey tide, only to stiffen and die the moment it touched the substance.

Behaviour
Plains Rats are highly aggressive and ravenous creatures. They breed with frightening speed and eat nearly anything; through sheer numbers alone they can easily overtake and kill groups of humans. When in a feeding frenzy, the rats will eat without regard to their own safety, knocking one another into fire, smothering each other, or drowning while chasing fleeing food. They are also known to spread all manner of diseases.

Plains Rats cannot swim very well, and will drown very quickly in river water. They appear to be nocturnal, or at least detest bright light, as they only leave their roofed city at night and are repelled by fire. They can smell Scarlet Night and avoid contact with anything that has touched the toxic fungus.

Anatomy
Plains Rats are large, black rodents with thin, fleshy tails. They have beady, bright red eyes.

Habitat
Plains Rats, as their name suggests, are found primarily in Opal territory. The vast majority of the rats live in the "City of the Rats", trapped by the Broad River on three sides and a man-made river on the fourth side.

Diet
Plains Rats will eat virtually anything. Cloth, food, plants, and flesh of all kinds are perfectly acceptable for the rats to eat. They will cannibalise dead Plains Rats when able and can strip bodies to the bone with frightening speed. They avoid eating metal, bone, and Scarlet Night, presumably because their teeth cannot break down the former two, and because the latter is toxic.