Cats may enjoy licking plastic bags for a variety of reasons, including the smell of the previous contents of the bag, the noise the bag makes, the texture of the bag on the cat's tongue and attraction to the cornstarch or lubricants the plastic is treated with. A serious condition, such as pica, may be present, causing the cat to lick and eat the plastic. Pica is potentially fatal.
Plastic bags that once contained food, such as those from restaurants and grocery stores, may attract the cat and encourage licking due to the smell remaining in the plastic. The crinkling of the bag as the cat plays with it and licks it can resemble the sounds of rodents running through leaves or grass. Products that the bags are treated with, such as cornstarch to keep the bags from sticking together and lubricants made of animal by-products like stearates, may attract the cat and encourage licking based on the smell. The chemicals used to make the plastic bag may also attract the cat, causing a flehmen reflex that encourages the cat to lick or mark the plastic by urinating on it. Cats who suffer from pica may chew on or eat plastic or other non-food items in an attempt to fill in necessary nutrients that are deficient in the cat's diet. While licking plastic does not necessarily hurt a cat, eating plastic may result in illness or death because the cat cannot digest the material.