Well... Cats are still predatory animals by nature even if brought up as indoor pets. They have hunting instinct which cannot be removed. But it would appear that eating what they have hunted is another issue entirely. It seems that they either have to learn it from another cat or they have to be hungry. None of which is Caspian's case. The creature that he has hunted is most likely Eurasian shrew.

Cat name: Clark, Caspian
Breeder: Ojos del Salado
Breed: Russian blue
Born: November 27, 2017