Summarize this article in one sentence.
If you have a large infestation of rats that have already taken up residence in your home or on your property, there are green ways that you can get rid of them. Pet cats are one such way, as cats instinctively prey on mice, rats, and other rodents, and have been used for a very long time in agrarian societies to keep pests away from grain and food stores. If you don’t have a cat, consider visiting your local shelter to see if they have any cats available for adoption. Inquire about whether any of them are known mousers. Like cats, some dog breeds-—particularly terriers—can be excellent rodent hunters. If you're more of a dog person and are able to take on the full responsibility of being a pet guardian, visit your local shelter and see what kinds of terriers they have available for adoption. Not only will the dog be able to hunt any rats that are already on the property, but they will deter new ones from moving in. Barn owls are found all over the world, and they love eating mice, rats, and other rodents. While you can't keep one as a pet to deal with your rodent problem, you can encourage a barn owl to take up residence near your property, and it will hunt and consume rodents in large numbers. Barn owl boxes are simple to make as a DIY project, or you can purchase them online. Peppermint and plants in the mint family may act as natural repellents for rodents, and there are a few ways you can use them around your house to deter rats:  Plant mint around your house, especially in any areas that you know rats frequent. Soak cotton balls with peppermint oil and place them around access points, such as doors and windows. Fill a spray bottle with one cup (240 ml) water and add in 25 drops of peppermint oil. Shake well, and spray this solution around the outside of your home, on doors, windows, and outbuildings. Rataway is a specially blended and concentrated fragrance that’s designed to remove the odors left behind by rodents and other animals. While it may not get rid of a rat that’s already in your house, it will prevent others from being attracted by the smells left behind by rodents that have already been there. Rataway gets mixed with water in a spray bottle and sprayed on areas where rats have been, marked territory, urinated, or left other odors. Second-generation rodenticides are poisons that will kill an animal with one dose, meaning other animals—such as pets—are just as likely to die from eating them as the rats are. Moreover, these toxins tend to stay in the body, meaning they can also poison scavengers and birds of prey.  Avoid rat poisons that contain ingredients like:  Difenacoum Difethialone Brodifacoum Bromadiolone If you have a rat infestation and are looking for a quick fix, there are poisons out there you can use that will kill the rats without endangering other creatures. First-generation baits are highly toxic to the animals that consume them, but are much less likely to poison other animals as well. These poisons require several feedings before a lethal dose is delivered. Look for active ingredients such as:  Chlorophacinone Diphacinone Warfarin or warfarin sodium salt Sodium salt

Summary:
Get a cat. Get a dog. Install a barn owl box. Repel them with mint. Use rataway. Avoid second-generation rodenticides. Try first-generation rodenticides instead.