Cinnamon will deter mice but cinnamon does not kill mice.
Mice hate the smell and scent of cinnamon and avoid the area where the cinnamon is placed.
You can also soak cotton balls in cinnamon oil and place them where mice are coming in and they will avoid those areas as well.
But if you really want to get rid of mice you need to set out mice traps such as those snap mouse traps and kill the mice otherwise they will just continue to reproduce and come back.
And you have to deal with them again.
Also seal up holes where mice come in your house and put dog food up when the dogs are done eating or cat food.
Keep pet food in sealed containers.