In Japan they were introduced in the 1970s after idiots bought them as pets because of a popular anime (Rascal). They’ve now spread to every prefecture and are pushing out native species like tanuki. There’s an active trap and destroy order for them throughout the country.

Your thyroid gland takes up iodine naturally, and radioactive iodine-131 is a common waste product from nuclear plants. Taking iodine pills in a nuclear emergency basically saturates your thyroid with safe iodine so that it doesn’t absorb iodine-131.