I was working as a custodian at an elementary school in Ypsilanti Mi after my shift was ending approximately 11pm and was leaving to go home I escorted a teacher to her car which was a common practice with her she was always staying late working she was a special education teacher of approximately 25 years of service i was talking to her on our way to her car as we were talking before she entered her vehicle i witnessed an object light up and take off (blink out) approximately 100ft from us tree top high when I noticed it starting to (light) up I told her to look she turned around and it blinked out as fast as she could turn then all of a sudden another one appeared next to it and was either invisible or? Just appeared, lighting up and taking off in another direction (east) I immediately asked her WOW! What do you think that was? And she said something to the effect it's not 'fireworks'. And asked me what I thought it was I automatically thought it was a disk shaped UFO, I have pretty much all my life believed in extraterrestrial life and have had other sightings throughout my life, we're not alone she said to me 'anyone would have to be naive to think we're alone in this universe' she then entered her vehicle and left, I went to my car and drove home, nervous and anxious to tell my family what I saw.