 Perhaps the best known element of cats ' hunting behavior , which is commonly misunderstood and often appalls cat owners because it looks like torture , is that cats often appear to " play " with prey by releasing it after capture . This behavior is due to an instinctive imperative to ensure that the prey is weak enough to be killed without endangering the cat . This behavior is referred to in the idiom " cat @-@ and @-@ mouse game " or simply " cat and mouse " . 
