Preventing coin ingestion in your child is easy: never allow them to be around coins. Easier said than done. Ultimately your toddler will find a stray penny.
When it comes to preventing that from happening, sometimes the best policy is not to bring it up. It’s what I call a “bean in the nose.” The idea is this: if you don’t want your three-year-old to put a coin into her mouth, the last thing you should do is tell her not to put that coin into her mouth. Because you and I both know that as soon as you turn around, the coin is going in her mouth.
This is called a “bean in the nose” because in the old days kids rattled uncooked beans around in cups as makeshift toys. Apparently it wasn’t uncommon for kids to stuff these things into their noses where they would absorb moisture and swell creating an obvious problem. And the idea of stuffing a navy bean into one’s nose isn’t something that toddlers think about on their own.
When it comes to small objects, less may be more. Keep quiet and do your best to keep coins an other small objects out of reach.