If you ever go into the attic space of an old farm house,

get to the top of the creaky stair case,

and look around to decide where to go,

but see a spot in front of you,

between the floor joists,

that appears to have been stepped into before,

and you feel glad that it wasn't you,

but wonder what that dimple,

with the light coming through,

might look like from the other side,

well,

this is what it might look like!

My recommendation:  when you go into the attic space and need to walk around, walk only on the rafter joists!