Cats are the enemies of mice. Their eyesight is very good, and can penetrate the darkness of night. They cover their dung with earth so that animals passing by will not smell it and know the cat is nearby.

In the Liber de natura rerum, Thomas of Cantimpré has a great deal to say about the cat. Its sight is so keen that it can see mice in the darkest cave with its "carbuncle eyes"; it is a dirty and hateful animal; it fights with buffones (some sort of poisonous insect or reptile), but must drink water after the battle to avoid drying up; they fight venomous snakes and are not killed by the venom; they like to play with people and express their joy with their way of singing (purring); they are so enamored with their own beauty that if they stand over a well to see their reflection they will sometimes fall in; they love warm places (i.e. fire) and burn their skin by being too lazy to move; and they fight with each other to defend their territory.