Some cats develop a compulsion to chew on and eat some pretty strange things. Hair bands are popular as are paper, plastic, string and especially wool. Sue P. writes:
Sue, despite what some would have you believe, we really have no idea why cats engage in this behavior. It's called pica (from the Latin word for magpie - a bird who eats just about anything) and it occurs in humans too. Theoretical causes range from a dietary deficiency to physical brain issues to behavioral disorders and even stress. The biggest danger to Aiden is intestinal blockage since things like plastic bags and hair ties can keep real food from getting through his digestive tract.
To begin with, you want to make sure Aiden has a clean bill of health from a veterinarian. A general checkup is in order, with additional tests if there's any indication of problems, especially vitamin and other nutrient deficiencies.
Once that's cleared up, you want to take a good look at Aiden's nutrition. Make sure he's getting everything he needs, which usually means shying away from most commercial cat foods available at the supermarket. We have a post on cat food recommendations here: http://kittyhelpdesk.com/help-desk/best-cat-food-and-food-bowls .
Just be sure that he's getting as complete a diet as possible. Besides a high-quality wet or raw food diet, he may need his meals supplemented with a teaspoon of pure pumpkin puree and a good probiotic. Remember, for full nutrition, you're not only feeding Aiden but also the bacteria in his digestive tract.
You may find some success in redirecting his behavior toward something that's good for him. Cat grass is an excellent substitute for the long, stringy things that many cats with pica like to chew and ingest.
It may also help to play with Aiden more often and more actively. Exercise alleviates stress and can help him to forget about his compulsion. When you see him indulging, don't overreact. Just remove the offending object and replace it with a fun activity that Aiden enjoys. Reward him when he's playing with toys without eating them by offering his favorite treats. Adding treat puzzles to his toys may be helpful because he'll be rewarded by a new behavior, such as rolling a treat ball around.
If all else fails, Sue, you may want to consider a pharmaceutical solution. There are several drugs for felines who have excess anxiety or depression and can help tone down stress-related behaviors. We'd suggest trying this only after exhausting all other options and only for a short time at first. Feliway, a synthetic cat hormone, has also proven to be effective and has the advantage of being readily available.
Sue, we know this can be a real challenge. Just don't give up on Aiden. It may take some time but we're certain you can find a way to minimize and possibly even stop this behavior. We wish you both all the best!