Sad to say that I think he's either dead or long gone at this point. My son is taking it hard. Came home this evening to see that on the feeding chart on the fridge where you mark the date of each feed and shedding he's written "dead" on the last line. He also has a memorial screensaver on his phone. You do tend to forget that he's still a missing or dead pet to a little one.
Still, nil desperandum just yet.
I've set the second and last bait out on the floor in a quiet spot and I'm off to bed as I have an early start to go to a funeral in the morning.
We, and you, will see.