From Save A Fox:

“This time of year, foxes go through something called the “October Crazies”. Despite the name, it usually lasts all or part of fall and even winter.

October crazies is just a nickname for seasonal hormonal fluctuations in foxes. The first year of a fox’s life is the worst of these fluctuations. It is akin to the rebellious teenager phase.

It’s their body encouraging them to leave their parents and find their own mate and territory. For older foxes, these fluctuations are not as severe, but do still occur. These hormonal changes lead up to mating season in winter.

These hormonal changes affect every fox differently, and some even become more friendly during this time. However, the first is more common.

Even spayed and neutered foxes will experience these fluctuations, but with less severity.”