Today I was walking my puppy at night (10:30 pm) around my neighborhood. Suddenly, the collar broke (it was old I think). So I decided, oh what's the big deal? I'll get one tomorrow, so for now, I'll just walk him off leash home.He follows me fine and we are about to reach our house when we see another person walking his tiny poodle.My puppy (6 month old lab/pit bull mix) started getting aggressive while he tries to jump and nip at the person/other dog.In day time, my puppy is completely fine with other people. At night, he becomes aggressive.This has happened once before with another drunk person at night around the same time.Usually, I see NO aggressive streak in her. It is only at night. What do I do to stop this? What do I do in case this happens again?