° ° ° ° ° ° °

° ° ° ° ° ° ° ° °

The common brown rat also, called the Norway rat or sewer rat, is a destructive animal pest. There is also a rat known as the Roof Rat common in South Florida. These rodents eat and contaminate large amounts of feed, damage structures by their gnawing and burrowing and spread diseases that affect livestock and people. 

Recognizing Rat Infestations 

The presence of rats can be detected by droppings or signs of fresh gnawing. Tracks can be seen in mud and on dusty surfaces. Runways and burrows may be found next to buildings, along fences, and under low vegetation and debris. 

Characteristics 

Norway rats are husky, brownish rodents that weigh about 11 ounces. They are 13- to 18- inches long including the 6- to 8 1/2- inch tail. Their fur is coarse and mostly brown with scattered black on the upper surfaces. The underside is typically gray to yellowish-white.  Roof Rats has a longer tail & body along with large round ears. Occasionally a smaller version with a slightly pointed muzzle called the House Mouse can be found as well.

Rats will eat nearly any type of food, but they prefer high-quality foods such as meats and fresh grain. Rats require 1/2 to 1 fluid ounce of water daily when feeding on dry food.  Rats have a keen sense of taste, hearing and smell. They will climb to find food or shelter, and they can gain entrance to a building through any opening larger than 1/2-inch across. 

Rats have litters of 6 to 12 young, which are born 21 to 23 after mating. Young rats reach reproductive maturity in about 3 months. Breeding is most active in the spring and fall. The average female has 4 to 6 litters per year. Rats can live for up to 18 months, but most die before they are one year old. 

Rat Control 

Sanitation: Poor sanitation and the presence of garbage allow rats to exist in residential areas. Good sanitation will limit the number of rats that can survive in and around the home. This involves good housekeeping, proper storage and handling of food materials and refuse and elimination of rodent harborage (shelter). 

Rat-Proof Construction: The most successful and permanent form of rat control is to "build them out" by making their access to structures impossible. Ideally, all places where food is stored, processed or used should be rodent-proof. Store bulk foods, bird seed, and dry pet food in metal trash cans or similar containers. 

Seal any openings larger than 1/4 inch to exclude both rats and mice. Openings where utilities enter buildings should be sealed tightly with metal or concrete. Equip floor drains and sewer pipes with tight-fitting grates having openings less than 1/4 inch in diameter. Doors, windows, and screens should fit snugly. It may be necessary to cover edges with sheet metal to prevent gnawing. 

Traps: Trapping is an effective method of control. Trapping has several advantages: 1) it does not rely on inherently hazardous poisons; 2) it permits the user to determine if the rat was killed and 3) it allows for the disposal of rat carcass, thereby eliminating odor problems which may occur when poisoning is done within the buildings. 

A simple, inexpensive wood-based snap trap is available in most pest control centers. Wire cage traps are another option. Bait traps with peanut butter, pepperoni, bacon, or chocolate attached securely to the trigger. The trigger should be set lightly so that it will spring easily. Set traps close to walls, behind objects, in dark corners and in places where rat activity is seen. Place the traps so that rats, following their natural course of travel (usually close to a wall), will pass directly over the trigger. 

Poison Baits (Rodenticides): Rodenticides are poisons that kill rodents. They are available as either non-anticoagulants or as anticoagulants.  

The non-anticoagulants cause death either via the nervous system or via the release of calcium into the bloodstream. Anticoagulants cause death as a result of internal bleeding which occurs as the animal's blood loses its clotting ability and capillaries are destroyed. The active ingredients are used at low levels, so bait shyness does not occur when using properly formulated baits.  

Most of these baits kill rats only after they are fed on for a number of days. These baits are known as multiple-feeds. Baits which are capable of causing death after a single feeding are known as single-feeds. However, rats do not die for several days. When baits are used, fresh bait must be made available to rats continuously as long as feeding occurs. Depending on the number of rats, this may take a few weeks. 

Bait selection and placement: Baits are available in several types. Grain baits in a meal or pellet form are often available in bulk or packaged in small packets. These "place packs" keep baits fresh and make it easy to place baits into burrows, walls, or other locations. Rats will readily gnaw into these bags to get an acceptable bait. Block style baits are also very effective for most baiting situations. 

Use of tamper-resistant bait boxes provides a safeguard to people, pets, and other animals. Place bait boxes next to walls, with the openings close to the wall, or in other places where rats are active. When possible, secure the bait station to fixed objects to prevent it from being moved.  

Sound and electronic devices: Rats quickly become accustomed to regularly repeated sounds. Ultrasonic sounds, those above the range of human hearing, have very limited use because they are directional and do not penetrate behind objects. Also, they quickly lose their intensity with distance. There is little evidence that sound of any type will give adequate control. 

Copyright © 2003 Care Pest  All rights reserved.

Home | About | Services | Email | Tips

° ° ° ° ° ° ° ° °