We recently moved into a new house a few months ago and have found mice

living under our back porch. All was well until we saw one run across the floor. I know, gross.
Anyway, we bought these repellent things that you plug into an outlet. They are supposed to give off a noise (can't be heard by humans) to chase the rodents away.
My questions is...do you think this can effect dogs? It says on the package that it is safe to use around dogs, cats, fish, and birds but I just wanted some other opinions. Thanks!