Rats and mice live everywhere in the world. The three that live with people are the common house mouse, Norway rat and the roof rat. Because these rodents carry diseases, ruin food and have been known to bite people, an infestation of them needs to be dealt with immediately. If the problem isn't that bad, you can probably deal with it yourself. If the infestation is bad, it's probably best to call in a pest control specialist.
Identify what is causing the problem. Is it a rat or a mouse? Mice are usually about 7.5 cm (3 inches) long and leave rice-size droppings. Rats can grow up to 30 cm (1 foot) long, and their droppings are the size of raisins. They also have smallish ears. Roof rats are graceful climbers with large ears that extend pass their eyes. If unsure whether there's a problem in a particular area, scatter some flour or powder on the floor in the suspected problem area. Place a food item such as a cracker or piece of cheese in the centre. Check for any tracks in the flour the following day.
Remove sources of food. Rats and mice aren't picky eaters, so any food scraps left around is a treat for them. After you feed the dogs or cats, clean the dishes of any remaining food. Make sure all of your rubbish is securely sealed in a can they can't get to.
Figure out where the rats or mice got into the house and make the necessary repairs. Many times, something as simple as a missing soffet will allow them entry into the house. Put screens on your window and keep your doors closed. If there are openings around pipes or cables, caulk or cement them. If you have drains in the floor, keep them sealed tightly. If there are any small holes or cracks leading to the interior, seal them. Mice can fit into a 6 mm (1/4 inch) crack.
Clean up your outside surroundings and destroy their homes. Remove any rubbish, discarded furniture, wooden boards, junk cars or anything else where they could take residence. Also, keep any weed growth to a bare minimum. If you have a bird feeder, keep it away from your house.
Set up traps inside the house. Place a mouse or rat trap along the sides of the wall every 1.5 to 3 m (5 to 10 feet). Also place traps inside cabinets and drawers. A fat and happy rodent won't travel far for food. The drawback in using poison inside the house is it's hazardous to children and pets. Also, the rodent won't die instantly. It possibly can then hole up inside the wall, die and stink.
Use poison bait outside of the interior living areas. A garage or a locked shed is a perfect place to use poison bait traps. Since many times the bait is laced with sugar, don't leave it in an area where other animals will be able to get to it. You should notice some of the bait being eaten, if mice or rats are present. Each bait station remains active for up to 2 weeks. Discard it once it's either eaten or after the 2-week period. Place new bait stations down if rats or mice are still present. If no more bait is being eaten, the rats are probably dead and gone.