I learned years ago that if there’s one thing I should never leave out, it’s plastic shopping bags. In my case, it’s just because the sound of my cats licking that crinkly material was enough to drive me batty. But for one of my friends, keeping plastic out of her cats’ mouths is a matter of life and death: One of her beloved furry friends actually ate enough of a plastic bag to result in a midnight trip to the emergency vet and surgery to remove the stuff from his stomach. One of my cats also had an odd obsession with licking the emulsion off photographs.

Why do cats do this? What’s up with this obsession with stuff that’s not very tasty and even potentially fatal? There are several theories as to why cats might be driven to frenzies of foolishness over those crazy polymers, and here they are:

1. Enticing food smells

Soft plastics are porous and they trap the odor of whatever was contained within them. Cats’ sense of smell is even stronger than dogs’, and since we put everything from meat to fish to sandwiches in plastic, it makes sense that even the faintest whiff of a tempting treat could lead to licking and perhaps even swallowing plastic.

2. Crinkly fun

A shopping bag makes all kinds of cool noises, which in some way mimic the sounds of little rodents scurrying around in the grass and leaves.

3. The corn starch factor

More and more plastic shopping bags are being made of biodegradable materials that contain corn starch. Some cats seem to find the smell and taste of corn starch attractive.

4. Lickable lubricants

Plastics are treated with stearates, which are derived from tallow. I’ve seen some sources that say lanolin (the oil that makes sheep coats feel greasy) is also used in the production of plastic. Either of these things could be tempting to a curious carnivore. Gelatin is also used in photo emulsion, so that may explain the bizarre allure of those old Kodak moments.

5. It’s a texture thing

Some experts think that the smooth texture of plastic feels good on a cat’s tongue. There’s some thinking that the temperature of the plastic may be a factor, too, but in my experience, plastic pretty quickly picks up the ambient temperature of the room it’s in.

6. Pheromones

Some plastics contain chemicals that may mimic pheromones or other attractants, and it’s possible that licking plastic could be an extension of the flehmen reaction (a behavior in which an animal curls back his upper lips, inhales, and often holds this position for several seconds). This could also explain why some cats like to urinate on plastic bags.

7. Mental short-circuit

Some cats get in the habit of eating non-food items. This condition, called pica, is sometimes considered a mental compulsion and sometimes thought of as an attempt to try and get necessary nutrients that aren’t present in the cat’s diet.

What do you think? Do you have any other ideas about why cats are obsessed with plastic? Do you have a plastic-crazed cat, and what plastics are his or her favorites? Sound off in the comments.

Learn more about your cat with Catster:

• Weird Cat Facts: 8 Reasons Your Cat Likes to Lick You
• 10 Sounds That Cats Make — and What They Mean
• 8 Things to Try When Your Cat Won’t Eat

About JaneA Kelley: Punk-rock cat mom, science nerd, animal shelter volunteer and all-around geek with a passion for bad puns, intelligent conversation, and role-play adventure games. She gratefully and gracefully accepts her status as chief cat slave for her family of feline bloggers, who have been writing their award-winning cat advice blog, Paws and Effect, since 2003.