Kids are really protective of things that they have labeled as “theirs”. Even though you, as their parents, were actually the ones to work and shell out the cash for it, the moment it touched their fingers, it became theirs. If they have siblings, then you know there’s going to be a bit of a war waged between them over who can play with what.
If you want to give your little one the peace of mind that their sister isn’t going to try to flush their favorite action figure, or their brother won’t read their diary to all their friends, you can get them the Stay Out Of My Room Alarm. This consists of two sensors and wristband combination that will let its wearer know when there is an intruder. It can send a wireless signal up to 100′ away, and the wristband will illuminate a light that corresponds with a sensor. There is an alarm and silence mode, and you’ll be looking at about $40 if you want to purchase one.