But every day, people swallow more mundane things that they shouldn't. \"In the adult population, they usually swallow the object by accidentally mixing it with their food,\" explains Farcy via email. Here are some of the most common, but dangerous, things adults swallow by accident:AdvertisementAdvertisement1. ToothpicksSwallowing a toothpick is not as common as you might think, but it's a serious situation if it happens. If the bones don't come out on their own though, an endoscopy might be required.