Rabbit's foot fern, Davallia fejeensis, are vigorous ferns. They can remain in the same pot until they become root bound. When they are root bound, the roots form a ball, with the furry rhizomes covering the exposed surface of the soil. When you repot a rabbit's foot fern you will also probably need to divide it to keep it growing at its best.
Some similar ferns with fuzzy rhizomes are squirrel foot (Davallia bullata), hare's foot (Polypodium aureum), and bear's foot (Humata tyermannii). These similar plants are sometimes confused, but you can use the same repotting methods for any of them.
Divide and Repot Rabbit's Foot Fern
Loosen the rabbit's foot fern from its container, and carefully slide the plant out. Repotting is best done in the winter, about January, before the new spring fronds begin to grow.
Trim all of the fronds back to the base of the plant.
Viewing the rhizomes/root ball from the top, divide it with a sharp knife into fourths. Each fourth should have sections of the rhizomes (the furry "foot" parts) and roots. Prune away about 1 inch of the lower portions of the roots.
Make a potting mix blend especially for your ferns. Use two parts peat moss, one part loam, and one part clean sand or perlite. Mix together well.
Place 2 inches of potting mix in the bottom of the new containers, and place each fourth of the rabbit's foot fern in a new container. Fill in around the sides of the fern with the potting mix. Keep the furry rhizomes above the soil surface.
Water after potting, and lightly mist the rhizomes. Keep the soil moist, and new fronds should appear in 7 to 10 days.