Human only species that kill each other?
Why did he say that in the movie? anyone with a decent knowledge knows that this is wrong. Did he actually say this in real life or is this just editet into the movie?
Apart from humans, the only animals known to kill for reasons other than survival (defending territory, fighting over females, for food etc) are chimpanzees and bottlenose dolphins. Both of these species have been documented killing other animals for what can only be described as "fun".
Chimps (whch are apes, like us, not monkeys) have been known to attack younger chimps and small monkeys for no obvious reason. Bottlenose dolphiins have been seen attacking baby whales and other dolphins.