An amusing route for those not suffering from claustrophobia.
Start at the lowest point on the crag, up the crack trending left to the ledge and belay 1. Up the first chimney you see, and belay at the top next to the cleft in the right wall and "rat hole" scratched onto the rock. Enter the Rat Hole above the chockstone, wiggle and squirm your way up to the light at the far end, tricky at the start with a taxing middle section and a sting in the tail, continue up and belay in the attic cave. Enter the Rabbit Hole at the back of the attic cave (not sure if you should enter at the highest hole), or the easier entry 3m lower, climb down (yes, down) until you see the lights and enter the real world again at the base of south chimney.
Borrowdale guide says "more exciting without a head torch" I say, take a torch or you will never get out.