The Brief: According to the internet, a rat-licker is someone who disregards public health guidelines like wearing a mask during a pandemic. It's a nod to how such a person would lick rats during the Bubonic plague.
Rat-licker is a slang term for someone who carelessly spreads disease. It’s a reference to the association between rats and the Bubonic Plague, though evidence indicates that it spread from fleas (which may have been on rodents) rather from bacteria on the rats themselves. The term was popularized in August 2020, during the COVID-19 pandemic as a reference to people who refuse to wear masks.
An Urban Dictionary entry by user “For The Greater Good” defines rat-licker as “A person who refuses to wear a mask, or take any of the basic precautions to help society prevent an air born illness during an epidemic. ( In reference to the bubonic plague being spread by rats. )”
The term was defined on August 15 and the following day, Urban Dictionary featured it as their word of the day. A derivation of rat-licker is bat-licker, a more COVID-specific term that references how the novel Coronavirus originated in bats. There is no direct correlation between rat-licker and the term ratf**ker, which refers to political sabotage.
Wait…”rat-licker” gotta catch on. pic.twitter.com/vB4kWyldse
— Ashley Reese (@offbeatorbit) August 16, 2020
You're a rat licker, that's what you are. pic.twitter.com/qoWYMmI1jg
— Antonia Lee Donnelly (@DonnellyAntonia) August 19, 2020