The woman lured hundreds of mice into a bucket with a toxic cocktail.
However, the extremely deadly trap did not breach animal welfare laws, Norway's highest court has now ruled.
At the end of last year, the woman behind the trap was convicted in two lower courts for violating the animal welfare act. According to the charges, the woman had taken the lives of hundreds of mice by luring them with chocolate into a bucket filled with water and antifreeze. There, they died.
The woman, a smallholder, posted pictures of the mouse massacre on social media and was subsequently reported by an animal rights organisation. As a result, she was fined 6,000 Norwegian kronor, which she refused to pay – leading to a lengthy court case.
The Supreme Court has now ruled that the act was justifiable given the difficult situation the woman found herself in, with a severe mouse infestation in her home.
I wore boots indoors when it was at its worst, the woman said in court, according to NRK.