Start Baby Mode and place the mouse out of the children's reach.
There is no danger as long as Baby mode is running let the kids play all they want, Baby Mode puts the Keyboard in Babymode meaning all key's will activate a funny animation and sound from a farm animal even Ctrl+Alt+Del ,Alt F4 or any other such key combination.
When the kids are done take the mouse and close Baby Mode, things are now back to normal, so take care.