attractive nuisance
noun
Law. a doctrine of tort law under which a person who creates or permits to exist on his or her land a dangerous condition attractive to children, as an unfenced swimming pool, is liable for their resulting injuries, even though the injured are trespassers.
a hazardous condition or object to which this doctrine is applicable.
But then you probably already know about this, and it may only come into play if and when one of the kids does get hurt.