It is from this video. It is at 21 minute.
Take a rat. Train it to press a lever ten times, it gets its food. Ten times it gets its food. Ten times it doesn't get its food. Ten times, you are not giving it its food. Get the rat good and frustrated. And with great realibility if there is another rat sitting there, it is going to sping around and bite it.
Does it mean to get the rat very frustrated?