There are 7 Diglett to find in Courageous Cavern.
Alolan Diglett #1
The Diglett is near the entrance to Loop Lagoon. If you enter Courageous Cavern on land from Loop Lagoon it can be found hiding against the cavern’s wall to your right.
Alolan Diglett #2
The Diglett is near the entrance to Loop Lagoon. If you enter Courageous Cavern on water from Loop Lagoon it can be found up on a ledge to your left. You can also enter the water from within Courageous Cavern near Diglett #1.
Alolan Diglett #3
If you enter Courageous Cavern from Loop Lagoon and follow the path up to the intersection you’ll see the Diglett straight ahead of you by a rock.
Alolan Diglett #4
When you enter Courages Cavern from Challenge Beach turn left and go down the ramp. The Diglett is hiding behind the first rock. Alternatively, if you just got Diglett #3 go right to access the ramp.
Alolan Diglett #5
When you enter Courages Cavern from Challenge Beach turn left and go down the ramp. From there go down the next ramp until you reach the three Pokemon Dens. The Diglett is by the Pokemon Den to the left.
Alolan Diglett #6
When you enter Courages Cavern from Challenge Beach turn left and go up the ramp. The Diglett is hiding behind the rock just before the water.
Alolan Diglett #7
When you enter Courages Cavern from Challenge Beach turn left and go up the ramp. Jump on you bike and keep riding across the water. Before you enter the passage that slopes downwards to Fields of Honor turn left into the room with a Pokemon Den and a rock. The Diglett is hiding behind the rock.