How do I get the chattering teeth?

Hint 1 of 5:

The teeth will back away from you whenever you get close to them.

Hint 2 of 5:

Maybe you can back them into a corner.

Hint 3 of 5:

Or if not a corner, at least some kind of trap.

Hint 4 of 5:

Like a hole in the ground.

Hint 5 of 5:

Open the grating near the fireplace.