Will sleeping with lights on keep mice away?

Sleeping with lights on will not reliably keep mice away, because mice are not strongly deterred by light alone and will still be active if they have food, warmth, and shelter. Mice are nocturnal and prefer to forage in the dark because darkness helps them avoid predators, so bright lights may make them slightly more cautious and cause them to stick to shadows along walls, under appliances, and inside cabinets where light does not reach, but it does not remove their motivation to find food. If mice have already established nests inside your walls, attic, or kitchen, they will continue to move around even with lights on, especially in hidden areas. Pest control studies and professional experience show that light alone does not cause mice to abandon an infestation and can waste electricity and disturb your own sleep without solving the problem. Some people try to combine lights with other deterrents like ultrasonic devices or strong smells like peppermint oil, but those also have limited and temporary effectiveness. What actually deters mice is removing food sources by storing all food in airtight glass or metal containers, sealing entry holes larger than a quarter inch with steel wool and caulk, reducing clutter that provides nesting material, and using multiple snap traps or electronic traps baited with peanut butter placed along walls.