How do you keep mouse out of swimming pools?

Answer 1

If you are talking about wild mice then the chances are that they are ending up in the pool because they are trying to get a drink. So perhaps if you made water more easily accessible away from the edge of the pool they would get their water from there and not fall in the pool. I understand wild mice are an unpopular pest but if its wild mice then it would be the only way to stop them short of building a barrier around the pool. Mice do not like to cross open ground, so if you can place low water bowls in amongst foliage or in dark corners, they will far prefer those water access points. It's also a kind act, for the animals who share our world.

Answer 2

Mice are afraid of Cats. This is common knowledge. Therefore if you wish to keep mice away from your pool, simply fill it cats.

Simple, but effective solution.