Plastic bags do not break down in the environment. It can take up to a thousand years for them to decompose. They can also harm animals in an ongoing cycle. When an animal that has eaten a plastic bag dies, the animal decomposes, but the bag inside of it does not. Once the animal has decomposed, the bag is released back into the environment in the same condition. That makes it available to be eaten by another animal, which will release the non-decomposing bag again when it dies. The incredibly long decomposition rate of plastic bags makes this an even bigger problem than it seems. More and more bags are introduced into the environment daily, which compounds the problem even more. Which information in the passage supports the argument that plastic bags are a threat to animals? Plastic bags are everywhere. Plastic bags are hard to get rid of. Plastic bags do not decompose once eaten. Plastic bags decompose inside the animal.