Predator urine and mint deter rats. To repel rats with predator urine, purchase the product at a local home and garden store, and sprinkle the urine around the affected areas of the garden. Mint deters rats when it is planted along pathways and around the perimeter of the garden. Maintaining the property is also recommended if rats are present.
If growing mint isn't an option, spread dried mint leaves or mint oil around the perimeter of the garden. Refresh the mint as often as needed to deter the rats. Mint plants are most effective when they are partially planted in an area where the plants are walked on, as this releases the scent of the plant.
To maintain the property, remove all debris, such as piles of brush and dense patches of vegetation, and mow the lawn frequently. Stack piles of lumber or firewood off the ground, and store other necessary items off the ground and away from fences. Use rodent-proof bird feeders, and remove pet food and water as soon as the pet has finished eating to further deter rats.
Rats are considered a health hazard, and trapping is recommended if other methods fail to deter the rodents. Place snap-style traps in the affected areas, and remove and discard trapped rodents immediately.