The very thing that makes magnets so much fun to play with is the same thing that makes them dangerous. They stick together. And if swallowed, they'll make their way to each other inside the body, even if things like small intestines stand in their way. At least 19 children have required surgery after swallowing the small, powerful magnets that are part of today's building sets, leading to recalls of the popular toys.

Though the toys have been recalled, they may still be in homes across the country. Read the CPSC warning about these kinds of magnets here to find out if you're household may be affected.