One option could be to perfume your home with scents that rats hate, like ammonia or the smell of mothballs (although mothballs can be toxic to humans, too). Other options include peppermint, eucalyptus and citronella, although none of them have been proven to be effective against rats.
Use natural deterrent methods
Try using ammonia, bay leaf, black pepper, cloves, peppermint oil or castor oil to keep the rats away.
Baking soda combines with the stomach acids to produce carbon dioxide gas which rats are unable to tolerate. In turn, it builds up within their system and eventually causes internal blockage and rupture. Soon enough, you will have the rat-free environment you always deserved.
Essential oils that may be helpful in repelling rats and mice include peppermint oil, lemon oil, citronella oil, and eucalyptus oil. You can make an essential oil spray by mixing 2 teaspoons of oil with 1 cup of water or rubbing alcohol in a spray bottle. Then spray it anywhere you see traces of rodents.
All you need to do is mix 2 – 2 and a half cups of ammonia, 100 – 200 mL of water and a 2-3 spoonful of detergent in a bowl. Then, put it to places where rats are usually seen. The smell of ammonia is very pungent that it instantly kills rats.
Eucalyptus or Peppermint oil can repel rats because they hate the smell. Another way to use a rat's sense of smell against them is to plant peppermint and catnip in strategic places. Diatomaceous earth is non-toxic to humans, but it can dry out rats until they die.
to eliminate sources of food, shelter, and water. Denied food, rats will turn to killing and eating each other, further reducing the infestation. Rats cannot live without food, water, or shelter.
Rats are afraid of human activity, mostly because humans are so much larger than they are. Rats also fear predators such as hawks, eagles, and other birds of prey. Other animals that rats are afraid of include your cat as well as rat terriers and other dogs that hunt rodents. Rats fear becoming a meal for a snake.
Chili Powder – Chili is believed to cause irritation in the nasal passage of rats when inhaled by the rodent. These rodents won't return to the same area where they smelled or ingested chili powder. To keep the rodents out, it's important to sprinkle the chili powder in the rat-infested areas every day.
Spread peppermint oil, cayenne pepper, black pepper, or cloves around the home's exterior to prevent the rats from entering the house in the first place. Apply your substance of choice generously along the line between your foundation and the ground.
“Peppermint oil, citronella and eucalyptus essential oils in their pure form are all smells that rats will dislike. “ A few drops of these oils in their pure form around the areas you know the rats have been should do the trick. Alternatively, soak cotton wool in essential oil and place it in rat traffic areas.
Homemade Rat Poison with Plaster of Paris
Start by mixing a cup of cornmeal with either a cup of powdered chocolate mix or sugar. Combine the above mixture with plaster of Paris. Mix well. Place the mixture in empty jars until they are about half full. Place the bait jars in the areas where the rodents frequent.
Rats are most attracted to high protein foods. When trapping rats, opt for baits such as peanut butter, hazelnut spread, bacon, dried fruits, or cereal. Snap traps should be placed perpendicular to the wall near signs of rodent activity (to find out where your area of high activity is, please see Diagnose Your Home).
A really dilute solution of dettol shouldnt hurt but should stink enough to keep rats out - but I am still a bit cautious about spraying even highly diluted acid anywhere around my engine. I had faced the same problem with my Swift, where the building rats had chewed through a whole bunch of wires.
Peppermint Oil
On a cotton ball use no more than 5 drops of 100% peppermint essential oil. Spread the oil on areas that you want rats to avoid, in your case, around the garden.
Pest Control – Eucalyptus is an effective remedy against pests like pantry moths, mice, or rats. To keep these pests out, place cotton balls moistened with two drops of eucalyptus oil in cabinets and drawers. For rodents, like mice or rats, the goal is to keep them outside where they belong.
Smells and Odors that attract rats
Odors and smells that come from pet waste, pet food, garbage containers, barbecue grills, birdfeeders, and even from unharvested fruit and nuts from plants can attract rats and mice.
Rats can easily chew through softer materials like cardboard and plastic. They can even chew through harder things like wood and PVC pipes. But rats cannot chew through steel. They can't chew through anything stronger than iron.