ratter

Ratter is a term with several distinct meanings in English. It is used as a noun to describe a person who informs on others, as well as a label for animals or activities involved in catching rats, and it is the title of a film. The senses are unrelated beyond sharing an etymological connection to the word rat.

In the informant sense, a ratter is someone who provides information to authorities about wrongdoing, effectively “ratting” on others. The term can be pejorative, implying disloyalty or betrayal, though it can also function descriptively to identify a role in a legal or investigative context.

In a canine context, a ratter is a dog bred or trained to hunt rats. Ratting has historical significance as a method of pest control and property protection. In Britain and elsewhere, small working dogs and terrier-types have been used for ratting. The term can also be applied to dog breeds marketed as rat terriers or to dogs known for rat-hunting abilities.

Ratter is also the title of a film released in the 2010s, a psychological thriller about a hacker who stalks victims through their electronic devices. Works with titles like this often explore themes of privacy, surveillance, and vulnerability in contemporary life.

Etymologically, ratter derives from rat plus the agentive suffix -er. Related terms include ratting (the act of hunting or pursuing rats), informant or snitch for the first sense, and dog-breed names such as Rat Terrier in discussions of the canine use of the term.