Animals hibernate during fall because food becomes scarce. Because of this, they can’t get their energy from their food anymore. So to conserve energy they hibernate. Hibernation is when animals sleep to conserve energy. During hibernation, the animal´s body temperature, heart rate, breathing, and digestion decrease for the animal to conserve energy.
A lot of animals hibernate during fall. For example, bears, squirrels, groundhogs, and dormouses hibernate during fall.
Because nights in the fall become longer, the green pigment that gives the leaves their green color, chlorophyll, gets destroyed. The colors that were hidden in the leaf become more, and more visible.
The days get shorter because of the way the earth is tilted. Because it is tilted the hemisphere of the south gets hotter because it’s closer to the sun while the north is colder.
Leaves fall because of the cooler weather, and shorter days, which decreases the production of a hormone called auxin. This causes the bond between the leaf and branch to weaken enough that the wind blows it away.