Cats are attracted to electrical cords and cables because of the animal by-products used in their manufacture to keep them pliable. Chewing cords and cables is not only destructive; it puts them at risk for shock. To counteract chewing, keep electrical cords tucked out of the reach, under furniture or rugs. If this is not possible, coat the cord with jalapeno pepper oil or wrap it in aluminum foil; cats are not fans of either of these items and it may discourage them. Another option is to purchase some PVC tubing, wide enough to both plug and cord, from the hardware store and thread the cord through that. If you still have problems with destructive chewing, get your pet checked out by the vet; she might have a tooth or gum problem.
Tip contributed by Animal Protective League