Lethal Rat Control

Trapping is a common way to lethally control Norway and roof rats. Trapping alone will not provide long-term control if attractions are not removed and areas where rats are entering buildings are not repaired.  

Because rats are neophobic (wary of changes in their environment), a trap may be avoided until the rats become familiar with the new objects along their travel routes. Even then, they will approach cautiously.

In addition, if the mother rat has become wary of traps, her young may learn to avoid them. This learning experience can make trapping and difficult in sites where control programs have occurred recently.

Trapping

Trapping has several other advantages: It does not rely on potentially hazardous poisons; it permits users to verify their success; and it allows for disposal of trapped rats, thereby eliminating dead-rat odors that may occur when poison is used. Many styles of rat traps are available:

Snap traps: Snap traps and other lethal traps are thought to be more humane than the use of poison because traps generally kill the rats instantly.

The traditional snap trap, or one of its variations, is an effective tool for killing rats, especially when there are only a few rats in a limited area. Rats will easily clean the bait off the old metal-trigger traps, but doing so is harder with the expanded version. Most supermarkets, hardware stores, or farm supply stores carry rat traps.

Don't set snap traps outside of a structure. Otherwise a chipmunk, raccoon, ground-feeding songbird, pet, or other animal may spring the trap killing or injuring the animals.

If trapping rats outside is necessary, use a trapping box. Commercial trapping boxes hold two traps, and have one or two small entrance holes. A trapping box also can be made from a wooden box with 2-inch entry holes at ground level. Place two snap traps facing each way inside, making sure the traps can operate freely with the lid closed. To minimize the possibility of trapping non-targeted wildlife, especially in rural areas, set the trapping box out at night and retrieve it or cover the holes at daybreak. Not retrieving the box early enough could mean the death of a curious chipmunk or other small animal.

Rats have a highly developed sense of touch due to sensitive body hairs and whiskers which they use to explore their environment. They prefer a stationary object on at least one side of them as they travel, thus they commonly move along walls. Such knowledge is helpful when placing traps.

Check all traps daily to reset any sprung traps and remove dead rats as quickly as possible. This is important to insure others won't become shy of the trapping device. Because rats may carry diseases, do not handle them without gloves; you can use a plastic bag slipped over your hand and arm as a glove. Once the rat is removed from the trap, hold it with your bagged hand and turn the bag inside out while slipping it off your arm and hand.

Rats are wary animals and careful attention to detail is necessary to trap them. Here are some tips:

• Set rat traps out as soon as rats are detected.
  
  
• Set traps where evidence of activity is found—along walls, behind objects, in dark corners, or where the rat is forced through a narrow opening, such as in the tunnel where the rat enters and exits a building.
  
  
• Move boxes and objects around to create narrow runways leading to the rat traps.
  
  
• Use as many traps as are practical so trapping time will be short and decisive. A dozen traps may be necessary for a heavily infested home.
  
  
• Place the trigger side of the traps next to the wall.
  
  
• Bait traps with peanut butter, banana, or bacon. If necessary, hold the bait on with a thread or a twist tie.
  
  
• If rats are traveling on rafters or pipes, fasten traps to them using screws, wire, or strong rubber bands. Secure the traps before setting them.
  
  Glue boards: Rodent glue boards are not recommended by Animal Evictor. Often rats and other rodents do not die humanly when these traps are used and slowly suffer to death on the glue board.
  
  Electronic traps: Traps that kill rats by electrocution are available on the market. These traps are considerably more expensive than the common snap trap and can be used safely and effectively only in limited situations. Like the snap traps, these traps catch only one rat at a time and then must be emptied. Twenty or more snap traps can be purchased and put to use for the price of one of the electrocution units. When compared with snap traps, electrocution traps have not shown sufficient advantages to promote their use.
  
  Live traps: Live traps are not recommended because trapped rats must either be killed or released elsewhere. Releasing rats outdoors is not recommended because of health concerns to people and the damage they may cause elsewhere. Because neither the roof nor Norway rat is native to this country, their presence in the wild is very detrimental to native ecosystems. They have been known to decimate some bird populations.
  
  

This information was provided by the Washington State Department of Fish and Wildlife, Russell Link and Michael Holmquist

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