During the colder months of the year in Florida, many people find that mice or rats are living inside the engine compartment of their car. If you detect a foul smell coming from your car’s ventilation system or mice droppings on the floor, you can be sure that you have unwanted guests inside. To prevent mice from taking shelter in your car, you can use one of two strategies: placing deterrents inside your car like cedarwood, peppermint oil, dog hair, or mouse traps, or alternatively, propping open the hood of your car to keep it cold under the hood.