Licking and Chewing Plastic Bags

Few feline habits look stranger from the outside. A cat that ignores an expensive toy will cross a room for a supermarket bag and settle down to lick it methodically, sometimes for several minutes at a time.

The most likely explanations are sensory. Many plastic bags are manufactured with slip agents derived from animal fats — stearates and similar compounds — and biodegradable bags frequently contain cornstarch or gelatine. To a nose fourteen times more sensitive than ours, a bag can genuinely smell faintly of food. Bags that have carried meat, fish or takeaway containers are more attractive still, and a cat does not need much residue to find one interesting.

Texture matters too. The cool, smooth surface against a tongue covered in backward-facing keratin spines produces a distinctive sensation, and the crinkling noise sits in a frequency range close to the rustling of small prey in undergrowth, which is precisely the sound cats are wired to investigate. Add the fact that pulling at a bag makes it move unpredictably, and the appeal is not really mysterious at all.

A minority of cases have a medical or behavioural driver rather than a sensory one. Persistent licking or eating of non-food material is pica, and it is associated with anaemia, hyperthyroidism, intestinal disease and dietary deficiency, as well as with boredom, anxiety and early weaning. Oriental breeds are over-represented. The distinction that matters is between a cat that licks a bag when it finds one and a cat that seeks bags out, chews pieces off, or has moved on to cables and fabric — the second pattern deserves a veterinary work-up.

The danger is worth stating plainly, because it is the reason this behaviour should not simply be indulged. Swallowed plastic can cause an intestinal obstruction requiring surgery, thin bags and handles present a suffocation and strangulation risk, and a cat that gets its head through a handle can panic badly. The practical answer is dull but effective: store bags in a closed cupboard or drawer rather than a low-hanging bundle, cut handles before disposal, and give the cat something legitimate to chew instead — a pot of cat grass, a silvervine stick, or a puzzle feeder that makes food take real effort to reach.