The guys just stop with something in their hand and do nothing else. There is empty space for them to leave things. There are also empty stocks if they want to use them. There is also bed available if they want to lie down. There are tasks to do if they want to work. But they just stand waiting to die, holding something in their hand. I was with 3 survivors when this happened. I should have been there by the 100th day.
*** EDIT :
So, I just realize that this is do to some resources that remain invisible over the floor. All these 24 feathers they are actually occupying places here and there. I know this, because when I asked to build a 2nd hammock, the guy went to an "empty" slot to take the material. Then it's hard to manage our space if we can't see the things that are filling it.
In the image below you see that there is at least 2 "empty" spaces or 4 if you count the spaces the girls are standing on.