Rat-baiting (or ratting) was a blood sport in which a dog is placed into an enclosed pit with a specified number of rats (typically, 100 rats), and bets are placed on how long it will take the dog to kill all of the rats. Usually the dog is of a breed, such as the rat terrier, that has been specially bred for this type of contest, in other words, bred for speed and biting force.
These dogs, known as "ratters," were quite good at killing rats, usually doing so by biting the rat and then quickly shaking their head to snap the rat's neck. A talented ratter could kill rats at the pace of about one rat every 5 seconds, although killing one rat every 4 seconds or less was considered a truly superlative performance. By the end of the contest, the dog would literally be covered in blood and gore.
Nevertheless, ratting was dangerous for the dogs, as rats, when cornered, typically turn and attack, so most ratters were missing at least one eye by the end of their careers and would be covered in scars from head to toe.
Ratting existed for centuries across Europe, but became especially popular in England in the mid-19th century, after popular blood sports involving large animals, such as bear-baiting and bull-baiting, were made illegal in 1835. Thereafter, blood sport enthusiasts turned to rat-baiting with a passion, and at the height of the rait-baiting craze, which lasted into the 1870s, there were over 70 rat-baiting pits in central London.
However, with the emergence of Victorian values, rat-baiting increasingly came to be seen as barbaric. Unlike bear-baiting and bull-baiting, however, which were banned primarily out of sympathy for the bear or bull, nobody cared about rats, so when rat-baiting was finally banned, it was because people had begun to feel sorry for the dogs. The last recorded rat-baiting in London took place in 1912, and the promoter was fined and made to promise never to undertake another rat-baiting promotion again.