Rats will leave your home if you introduce a smell that drives them away. This gives you a natural rodent control method that doesn't introduce chemicals into your home and resolves your rat problem without killing them.
The answer is PEPPER-- but don't try black pepper for rat control. Go with cayenne pepper instead or a hot pepper sauce.
Sprinkle the dried spice in areas that have a proven rat presence. When the rats get a whiff of the pepper, they'll move out. Repeat as often as needed, if the rodents move elsewhere in your landscape or if new rats appear.