My cats both have a thing for licking and trying to chew/eat tape on card board boxes (due to the glue adhesives), so I have to monitor them and try to ensure there is none they can get a hold of. They youngest is the worst! He also likes to chew card board boxes, steal and drag away anything that resembles a metal chain or string of plastic Mardi Gras beads, steal my tub's plug, and chew on the top of plastic water bottles, and even chew on metal, and electrical wiring (scary). He even got to the point where he was licking my bathroom hand soap! I had to remove the soap and switch to hand pumped soap. *shakes head* No clue why he does all of this, he has no illness, he is just odd. *shrugs* His odd behavior has cost me several $300-$400 dollar Vet visit bills for various tests and stomach x-rays (not to mention having to sedate my cat for the Vet trip and/or treatment, which is not healthy to do regularly. As I get scared he has possibly eaten something that could twist his stomach (commonly known as flipping a stomach) or cause a blockage. The only thing that seems to work when I can find a source for it, is "Bitter Apple" for cats (NOT DOGS). It is a spray that you spray on whatever you do not want them to chew/mouth/eat, and the taste is pretty bad (but not harmful to them). Think dog when it tastes something awful and it does that tongue thing where they try to get whatever it is out of their mouth, well, that is the standard reaction to bitter apple (yuck face). I recommend trying that on the items you do not want the cat to eat/chew/mouth, etc. You can also try the compressed air motion detector training aid, setting plastic somewhere that you can monitor, placing the spray compressed air close enough to have the motion detector go off when your cat comes near the plastic (so it gets a blast of air, and a loud sound), and see if that helps. Something I have noticed, several pet toys (cats and dogs) are now offered with a water bottle inside of some stuffed animal that has no actual stuffing, so the pet hears the crunching crinkle sound of the plastic when he/she chews on it. I would encourage you to remove and get rid of any toys that have a plastic water bottle inside, as they not only hear the 'fun' noises, but they can smell the plastic inside the material.. Lastly, your cat could be attracted to the adhesive glue on the plastic, or just the plastic itself, just be aware and careful of this, and don't let her/him chew or eat it, as this could cause some blood toxicity to build up (like metal is toxic in a digestive track), plastic is typically a Low Density Polyethylene (LDPE), poly-vinyl chloride (PVC or CH2=CHCl), Polyethylene Terephthalate (PET or C10H8O4), Plastic bottles can leach a toxic chemical called Bisphenol A (BPA or (CH3)2C( C6H4OH)2), and probably would not show up on a standard blood test, unless the Vet was specifically knowledgeable about what exactly her/she was testing to look for during the testing, the same as if a Dr. gave you a blood test, they too would have to specify WHAT it was that they are testing your blood sample for levels of, and I would expect it would take a specialty lab and special testing. I hope the above helps you and your feline, Try the Bitter Apple for Cats AND/OR the Spray Compressed Air Motion Detector Deterrent! My boys and I wish your Family of two and four legs, Good Luck and a Long Healthy Life together!