So I tried to get it down by scraping an office paper box lid attached to the 4m pole I use to adjust the server room A/C vents, but couldn't find it. I didn't even know which section of duct it was on. I tried taping a mirror to the pole but the mirror was too small. And then it hit me: TECHNOLOGY!
Cellphone + duct tape + 4m stick =
And from there it was easy to scoop it down with the box lid on top of the stick. Justin was surprised to see the rat rescued when he got back from wherever he was.