Brainlet food question...

No.12310061 ViewReplyOriginalReport
So I understand that things need to eat to survive. But what i'm confused about is, how do things know what to eat if they don't know what food is? Like how does a bird know to go to those specific nuts or even know what it's diet is? Like how does a Lion know to eat a Gazelle? Or how do Gazelle's know to eat grass?