Since the mice are in the attic there should be no children or pets around that can be harmed by anything you put up in the attic.
To get rid of mice in the attic I would recommend using some mouse traps or put out some mice poison to kill the mice.
Either way you need to kill the mice so they won't come back and damage things such as wiring etc.
Mice can chew electrical wires and cause a house fire so you need to kill the mice before they cause an issue.
I have put mouse traps and mouse poison in my attic before to kill mice and both worked.
You could also use some glue traps for mice to get rid of them.