两万年前的冰河时代，超级不靠谱的希德（约翰·雷吉扎莫 John Leguizamo 配音）带领海狸、食蚁兽、雕齿兽宝宝们展开野营旅行。希德自称森林的主人，大自然的儿子，但看起来它完全没有任何野外生存的经验，先是被马蜂狠命地蜇了一通，还跌落悬崖，接着小家伙们又在它的带领下成功迷路，希德还误尝有毒植物脑袋肿得像个皮球。虽然承受着来自小家伙们的不信任感和鄙视，可是这个超级自信的家伙丝毫不为所动，继续在它犯傻的道路上越走越远。此时此刻，无论是希德还是小宝宝们都没想到，它的无心举止将创造怎样神奇的地貌与历史……...
Returning from vacation, the Miller family find their home has been broken into. After cleaning up the mess they continue with their lives, shaking off the feeling of being violated. But little do they know the nightmare has just begun....
