Plug up any Openings. Unlike mice, rats need a lot of water (1 oz.), so they may travel in and out of your house. That’s why it’s important to seal up any cracks, holes, or entry points. Remember, if the hole is the size of a quarter, it’s big enough for a rat. Maintaining a Rat-Free Home. Rats come into your home looking for food, water, and shelter. As long as you deprive them of food and water, and make it difficult for them to get in, your home will be less attractive to them. Rats can eat just about anything and, while they require more than mice, rats don’t need a great deal of food (1 -3 oz. daily). To prevent future rat issues, be careful with how you store your food and scraps. Keep food in sealed containers and clean up any spills or crumbs.