what reason does the general give for hunting humans

"Zaroff has abandoned hunting animals because he finds no challenge in hunting them anymore. According to Zaroff, an animal's instinct for survival is no challenge to a one man killing machine like he is. Zaroff wants to hunt an animal that can reason. This, of course, means human beings. Zaroff spends his days hunting people he traps on his island. Rainsford is his perfect quarry because he not only can reason, but he is a world renowned hunter as well. Yes, it's the old story of the hunter becoming the hunted. Zaroff gets to have his kicks hunting a guy who can make a Burmese Tiger Pit.