It takes a young child just a fraction of a second to reach for some tempting object and swallow it. Even the most vigilant parent will occasionally arrive too late to stop the child.

But in most cases, there is no reason to panic.

for example, says Allison Brindle, MD, at the Cleveland Clinic Children's Hospital, a swallowed penny will probably pass right through the digestive tract. Parents need only check their child's feces to make sure the penny passes.

Other commonly swallowed items: crayons, gum, pet food, dirt, and bugs. None of these is toxic, so they shouldn't be cause for concern. One exception: grass that has been treated with pesticides.

However, two swallowing two common objects must be treated as an emergency: batteries and magnets. Batteries may leak dangerous chemicals inside the body, and magnets may adhere to each other across tissue and become lodged in organs. In either case, a trip to the emergency room is in order.

Of course, anytime a child is choking on a swallowed object, their airway may be obstructed and you need to take immediate action.