Destructive chewing by cats is undesirable, first, because of the potential danger to the cat, and second, because of damage to family valuables. Causes of destructive chewing by cats can range from teething in kittens to curiosity, to boredom, and even (surprise!) because of a nutrient deficiency. Kittens, like human babies, explore with their mouths, and these habits carry through to adulthood.
As always, if there is a chance a medical condition may be involved, be sure to take your cat to your veterinarian to eliminate that possibility..
Wires and Cords
Chewing on these cords poses hazards to your cat, from minor shock to death. Cats primarily chew on cords out of boredom, especially if left alone during the day. Try to provide plenty of "play alone" toys for your cat or kitten, including wall or door mounted toys they can swat or bat around, cat towers to explore, with attached toys for added interest, even an arrangement of cardboard boxes on the floor to form a tunnel, with holes cut through the sides.
To handle the cord situation itself, you need to devise a way to cover the cords, discourage access to them, or make them unpalatable for chewing.
- Cover the cords: Many computer supply stores carry pre-split hollow tubing for covering cords and electrical wires, as well as kits for managing computer cords. If you're handy with a utility knife, you can purchase flexible poly tubing in several diameters in most building supply or hardware stores. Slit one side of the tubing, then cut it to length for each cord. You might also try larger "corrugated" tubing to run several wires through if that works for you.
- Discourage access to the cords: Try applying several rows of double-sided sticky tape to the floor surrounding a large cord tangle (such as frequently happens with computers). Cats will be reluctant to walk across the tape. Another excellent tool for keeping cats out of any undesirable area is the SssCat! cannister by Multivet. This product is a three-pronged training tool which works with a motion detector atop the cannister which triggers a high-pitched alarm and a quick spray of harmless material. It's a lot more expensive than bitter apple spray but well worth the cost in its versatility for training purposes. Buy SsssCat! at Amazon
- Make the Cords Taste Bad: By far one of the best training tools for any kind of destructive chewing is bitter apple spray. It is guaranteed to leave a bad taste in your cats mouth, one that he won't long forget.
- Try CritterCords Cord Protector, to cover cords.
Cats have a natural desire for greenery to chew, and your live houseplants might become a target. Some of these plants can be extremely toxic to cats, and for your cat's safety, you need to learn to recognize and get rid of these plants. Check this list of toxic plants to see if any of your houseplants are on it, then either discard or make those plants completely unavailable to your cat. For other plants, try the bitter apple spray or the Ssscat! product.
Fabric and Leather Chewing
Wool chewing falls under the realm of OCD. For the kind of chewing behavior we're discussing here, the best way to discourage such behavior is to offer other 'legal' chewing sources for your cat, e.g. chewable soft toys. I've even seen wool mice, which might be a perfect substitute for your mohair sweater. Other cats will chew on leather gloves, or even shoes (rubber flipflops come to mind). Jaspurr loves to chew newspaper. He doesn't eat it, he just rips off small pieces and spits them out, and soon is surrounded by newspaper confetti.
If you can't put away all the fabric and leather items your cat likes to chew on, try the bitter apple spray on the area where he usually chews, but test it first on a small hidden seam.
Kittens and Chewing
As mentioned above, kittens often chew because they are teething (around three to six months). All of the methods described above will work, especially the toys, but there is one free tip that works wonders with kittens' teething: plastic drinking straws, especially the large ones used for milkshakes. They provide the crunchy contact kittens need, and they make a great interactive toy. You can derive lots of interactive play by teasing your kitten with the straw, then let him "capture" it and watch him proudly carry around his "prey." Adult cats may remember their straws, so it's not unusual to see one of them batting one around the floor.