imagine these are a group of lions.

好了假设有一个师群
And cooperating means cooperating on the hunt,

策略合作表示一起去捕猎
it means using a lot of energy going after

和别的个体一起去捕猎
as you cooperate in a group while hunting.

这要消耗大量的能量
And defecting here would mean not working hard on the hunt

背叛表示捕猎的时候偷懒
and letting the other lions catch the antelope or whatever,

让其他的狮子去猎杀羚羊或者别的动物
and then just sharing in the spoils: so "free riding" basically.

自己去分享别人的战利品坐享其成
Or another example, think about ants with an ant nest,

或者再举个例子比如蚁巢的蚂蚁
imagine this ant nest has been attacked by

假如蚁巢遭到了攻击
I don't know what, some other creature.

我们也不知道被什么生物攻击了
You could imagine that cooperating is joining in, in defending the nest,

可以把合作想象成齐心合力奋勇杀敌
at the risk of being hurt

这可要冒着受伤的风险