What scares rats away at night?

Rats are nocturnal and most active at night, so scaring them away at night relies on exploiting their natural fears of predators, open spaces, loud noises, and bright lights. The presence of a cat or dog, especially one that actively hunts, can scare rats because rats can smell predator urine and saliva and hear predator movements, causing them to avoid open areas and stay hidden in walls and attics. Bright lights can make rats cautious, as they prefer dark, covered routes along walls, so motion-activated lights in garages, basements, or yards may cause temporary avoidance, though rats will still move in shadows. Loud, sudden, unpredictable noises like banging, clapping, or ultrasonic devices that emit high-frequency sounds may startle them momentarily, but rats quickly habituate to constant noise and return if food remains. What truly scares rats in a lasting way is lack of cover and lack of food, so sealing entry holes with steel wool and caulk, removing food sources by storing food in airtight containers, and eliminating clutter that provides nesting sites is more effective than any scare tactic. Traps that kill quickly also create learned avoidance of specific locations. For best results at night, combine sealing, sanitation, and multiple rat-sized snap or electronic traps placed along walls where droppings are found.