These cats are called bag biters. Many cats are bag biters.
This cat behavior is still a mystery to me. Some cats bite bags more than others. Most feline behaviorists have come to believe that cats can smell the odors in the plastic, and find it simply irresistible to bite. Also, it is possible that the cats enjoy the coolness and texture of the plastic. Other behaviorists believe that it may be a feline “oral compulsive” behavior, similar to a cat trying to “nurse”.
Cats probably also enjoy the sound that plastic bags make when they chew them. This is very similar to many of the crunchy cat toys that owners by for their cats. When cats bite their prey, usually it will make a sound. Therefore, it is possible that biting a bag is similar to hunting and catching prey.
Plastic bags can be extremely harmful to your cat, so you should try your best to keep them away from your cat. If your cat eats the plastic, it can result in a variety of health problems. If your cat ate a plastic bag, you should speak with a veterinarian to make sure that your kitty is healthy!