I believe you have already read the news that a kid Rushed to Surgery for Swallowing Rare-Earth Magnets. Rare earth magnets are so strong that, a small piece could have enough magnetic force. That also means the rare earth magnets we are using in our daily life are usually of small pieces. It's fairly easy for kid to swallow them, not say other potential risk to electronic stuffs, pinching finger and skin.
So keep all rare-earth magnets or small stuffs with strong magnets out of reach of kids. It's really dangerous.