The Norway rat and the roof rat are the two most common rats that invade homes, and both can be very destructive. Setting traps can be an effective method of eliminating rats from your home and is safer and generally more reliable than using poison. Where you set traps is important for success but just as important are baiting properly and understanding some basics of rat behavior so you can target them effectively.
1. How Do I Know If I Have Rats?
Rats are nocturnal, which means they are most active at night, and they live in hidden areas, so you can have a major rat problem in your home even if you never see any. Because of this, you need to keep an eye and an ear out for signs of rodent presence:
- Live or dead rats
- Droppings, especially around human or pet food or in or around trash areas
- Noises in the dark, such as scratching sounds from the attic or in wall, floor, or ceiling cavities (behind the drywall)
- Nests or piled nesting materials in hidden areas, including areas with exposed insulation
- Gnawed wires or wood
- Burrows around the yard or under the home or a garage, shed, or another outbuilding
- Smudge marks on walls
- Rodent hairs along paths, in nests, or near food
2. How Do I Know That It's a Rat, Not a Mouse?
At 9 to 11 inches long—plus the tail—rats are much larger than mice. Rat droppings are 1/2 to 3/4 inch in length, but mice droppings are only about 1/4 inch.
3. What Do Rats Eat?
Rats will eat just about anything, but they prefer grains, meats, and some fruits. Rats eat a lot, about 10 percent of their body weight every day.
4. How Long Will a Rat Live?
Rats generally live about a year, but they can live much longer if they have warmth, shelter, and food.
5. Is It Possible to Find Rats in My Attic?
Roof rats, as their name indicates, like high places. They build their nests outdoors in trees or tall shrubs and indoors in attics or upper levels of the home. Roof rats are very good climbers and can get into the home by running along tree branches, cables, or wires.
6. Where Should I Put Rat Traps?
Traps should be placed where the rats are. Look for signs of nesting, gnawing, and droppings. Place the traps right up against the wall in secluded areas where rats are seeking shelter and along the routes that rats usually travel. Common travel routes, called runways, usually follow walls, since rats prefer to move along the perimeter of a room rather than out in the open. Look for signs of rat movement, such as droppings or light scuffs, scratches, or soiling along runways.
7. Why Are My Traps Not Catching Any Rats?
Unlike mice, rats are fearful of new things, so they may simply avoid a new trap set in their path. If they happen to set off a trap (such as by brushing it or sniffing around it) without getting caught, they may be spooked by the trap and will not return to it. To help prevent making the rats "trap-shy," you can place unset, baited traps first. Then, when the rats get used to them being there, put bait in the traps and set the triggers.
Contrary to popular belief, cheese is not the best bait to use in traps. Dried fruits, unshelled nuts, or even pet food can be attractive to rats. Be sure to attach the bait to the trap so that the rat cannot remove it without springing the trigger. The bait can be attached by tying it with thread or fine wire or even gluing it in place. Some traps have a small cup for holding the bait; placing a small amount of bait, such as peanut butter, inside the cup forces rats to work harder for the bait, increasing the chances of triggering the trap.
9. I Think I Have Rats, but Why Don't I See Them?
Rats are nocturnal creatures, so they are most active between dusk and dawn. If you do see rats during the day, it usually means that the nest has been disturbed, or they are hunting for food, or there is a large infestation.
In a single year, one pair of rats in the home can generate more than 1,500 young! This is because rats as young as 3 months old can breed and have babies. Each female can have up to 12 babies in each litter and up to seven litters in a year.
11. How Do Rats Get in My House?
Adult rats can slip through 1/2-inch holes and gaps, and young ones can get through even smaller spaces. They can squeeze through holes that are much smaller than you would think is possible. Rats will also gnaw on little holes to make them large enough to squeeze through.
Do's and Don'ts for Trapping Rats
Trapping rats is similar to trapping mice, but rats require larger traps, and they can be smarter about avoiding traps that don't entice them properly or scare them off somehow.
- Don't use poison as bait in a rat trap. Poison does not make traps more effective, and it unnecessarily introduces risk to pets and people in the home.
- Do reuse rat traps. The scent left by a rat caught in a trap will not deter other rats from the trap; rather, it can attract them to the trap.
- Do be patient when placing traps. Rats may not approach a trap for several days after it is placed. As long as the bait is properly positioned in the trap (and hasn't been taken by a rat), you can leave the trap for many days or even a couple of weeks.
- Don't touch traps with bare hands. It's best to bait and set traps while wearing gloves or using tools or utensils instead of your hands. Human scent on traps can repel rats.
- Do place multiple traps. Set single traps in more than one location to increase the chances of a rat encounter.
- Don't place traps where children or pets may come in contact with them. Try to keep traps out of living areas or frequently used storage spaces. Otherwise, you can close doors and warn children to stay out of areas containing traps. Be especially careful about setting traps outdoors, where it may be easily encountered by pets or wild animals.