Getting rid of rats without using poisons or traps requires more work in the short term, but pays off in the long run. Instead of getting rid of the immediate problem, you'll prevent future problems by making your home less desirable and excluding rats from entering. However, if rats have moved into your home in the fall, it is nearly impossible to convince them to leave until the spring unless you trap or kill them.
Seal up any holes you find in the foundation, under steps or decks and in the walls with cement, polyurethane foam sealant or caulk. Stuff holes with stainless steel scouring pads or cover them with a 1/4-inch wire mesh before sealing them to prevent re-entry. Don't forget to seal around wires and pipes to block any air flow in or out that might encourage a rat.
Install a tight-fitting lid onto your sump pump and a heavy, 1/4-inch mesh screen over your sump pump outlet.
Close threshold gaps on any exterior doors. Check doors, windows and screens to ensure they all fit tightly. Keep patio and garage doors closed.
Dump any water that may accumulate in toys, flower pots or equipment.
Remove any outside sources of food for rats including dog droppings, vegetable gardens, pet food, open garbage cans, bird seed, food scraps and compost piles. Pick up any fruit or nuts that have fallen to the ground. Talk to your neighbours about eliminating any food sources rats may be finding in their yards. A rat may be living with you and feeding at your neighbours.
Store firewood and other materials 12 to 18 inches off the ground. Don't store them against the side of your house.
Remove any junk and trash around your home and mow any tall grass where rats may be hiding.
Prune hedges so there is 2 to 3 feet between your home and it. Remove any tree limbs that are within 3 feet of your roof. Thin or remove hedges and vines so they are away from the building.
Store foods in hard plastic containers and not plastic bags or cardboard boxes.
Pick up any pet food your pet hasn't eaten.
Rinse out your kitchen sink with bleach and boiling water once a month. Use garbage disposals as little as possible and never throw grease down the drain. Rats can follow the smell of food up the pipes and into your toilet.
Keep your toilet lid down when you are not using it. If you find a rat in your toilet, squirt some dishwashing liquid in the bowl, wait a minute and flush it down the drain.