Could it be ancient aliens is full of bull?

OK today I am watching ancient aliens - They found perfectly round balls of granite near a stream. Wow what a surprise. You cut something almost round put it into a stream or on a beach it turns into a perfect sphere . We have a whole beach of granite balls orange and gray granite right here in Maine, it is called pebble beach or something. Ancient people could know rocks get round when water runs on them continuously > Why doesn't this show know.