The rat is a common feature in spoken English and comes up frequently in symbolism, plays religion and at the moment, the news. They are very evocative little creatures. For many they summon images of the plague being spread around mediaeval London as they scurry about infecting people.
Probably as a result of the rat's superb ability to spread disease they have earnt themselves a swearword. The word 'rats' is used as a mild expletive in many areas of the world including America, the Isle of Man and others.
Oddly the Romans had no separate word for rats or mice, instead of referring to them as 'mus maximus' and 'mus minimus' respectively. The Chinese are very fond of the rat and have it as their primary Zodiac symbol. Individuals who find themselves born under this sign are thought to be intelligent and sociable, like rats. They get on well with horses, but not with dragons.
In 'The Pied Piper of Hamlin', the piper is hired by the villagers to lead the rat infestation of the village away. Unfortunately they do not pay him and so he leads their children away as well. Not a very nice story!
The Hindus hold the rat in higher esteem than any other group in the world. They believe the rat to be the worldly incarnation of Ganesh, the elephant god. This leads them to worship the rat and allow them to over-run the Karni Mata temple in Uddar Pradesh Province. Daily priests feed the rats with grain and milk. Travellers make pilgrimage from all over the world to visit this incredibly famous temple.
Rats are featuring highly in the news in the UK currently. Giant rats are seen running in hordes along alleyways. Super-rats have been found which are resistant to many current poisons and repellents. These things are making it harder to keep the rat population under control. In response Hammer Technologies have developed their new rat repellent flooring to keep these little animals at bay. Because it uses completely new technology to control rats it is often effective where other methods have failed.