After the grey squirrel incursion yesterday I didn't hear a peep out the red squirrels, and there was no activity on the crittercam, so I conducted an experiment

I put some cardboard over the hole I've seen them go through, and set up the cam...

I hoped that they'd moved out, but the cam yielded 27 x 30 second video clips of a squirrel leaping. Eventually they tore a hole in the cardboard.

I am hopeful that this means that this is the only squirrel entrance to the house!