prey on
phrasal verbprey on/upon somebody/something
(of an animal or a bird )兽或鸟 to hunt and kill another animal for food 捕食;猎获 Hawks prey on rodents and small birds. 鹰捕食啮齿动物和小鸟。
to harm somebody who is weaker than you, or make use of them in a dishonest way to get what you want 欺凌,坑骗,敲诈(弱者)