The Europeans had a Halloween custom of hollowing out a large turnip, carving eyes, a nose and a mouth on it, and lighting a candle inside. The turnip face was supposed to fool demons. Different groups of animals prepare in different ways. A colony of ants stores food underground. A brace of ducks flies south, toward warmer weather.
Autumn brings changes to many trees.
Leaves that were once green turn yellow, orange and red. That means the surface water is cooling off and sinking to the bottom, which forces the water at the bottom of the lake up to the top. This process increases oxygen levels in the water, something that helps the fish survive the long, cold winter ahead. When a lake turns over, it also stirs things up, which means more food for the fish that need to fatten up for the winter Owls are out marking their territory. You can probably hear them hooting in the night.