RSS Feed
Email this article
Printer friendly page

Ask Rick A Question

Norway Rats

Summary: Norway rats are the dominant rat species in North America and are also known as the common rat. Norway rats are well adapted to live near humans, so getting rid of an infestation can be difficult.

Rats might very well be the smartest animal that walks on four legs. A study in 2007 showed signs that rats have metacognitive ability, meaning that they can think about thinking. This self awareness had been previously thought only to exist in humans and some primates, but rats have proven themselves cleverer than we ever gave them credit.

Standard snap traps, such as the Victor snap trap, should be placed near the places where rats have been traveling. The traps should be placed directly against the wall, with the trigger side of the trap next to the wall. Quite often I see traps placed near walls, but those poor-sighted rodents run right past it. I also see wrongly-placed traps placed horizontal to walls. If the rat comes from the direction opposite to the trigger, nothing is going to happen.  

Here is the secret to trapping. Do not set the traps the first time you set them out. Instead, bait them with the food you know the rats have been eating and let the rats take the food several nights in a row, allowing the rats to gain confidence around the trap. Remember, rats will avoid new objects for several days, so you need to trick them by building their trust before you set the trap.

Placing several traps next to each other and in multiple locations can increase your kills. If you find that a type of bait is being rejected by the rat, try another kind of bait. Peanut butter, chocolate, or some hot dog meat usually works well, but the bait has to remain fresh. Old, stale peanut butter will not attract a wise old rat.

Norway rats are the most common rats found in North America, and the largest. They rats are often referred to as common rats, brown rats, sewer rats and wharf rats. The Norway rat can grow up to ten inches long and posses a tail of an additional ten inches. Most male rats weigh around 350 grams, but can weigh more than 500 grams. By the way, that converts to only a little more than 17 ounces or just over one pound. We've all heard stories of rats the size of cats, but the reality is that the sudden appearance of an adult rat with its back hunched up and its fur sticking straight out, makes the rat appear much larger. If someone wants to bet you ten bucks that he can show you a five pound Norway rat, raise the bet to fifty dollars and prepare to collect.

Norway rats have dark brown fur, sometimes with black patches, and a grey belly. They have a blunt nose, small ears, and a semi-naked tail that is almost as long as their body. They eat almost anything as long as it is clean and fresh. Contrary to popular belief, they do not like rotten or spoiled food. They eat fresh and nutritious food like meats, grains, some fruits, and sweets. They also require at least a half ounce of water a day.

Having an unsanitary living environment might attract rats, especially if there is a water source. They will get into garbage bins, but only to search for recently discarded food. Norway rats can also chew through many materials so even food stored properly can be at risk of contamination.

The Norway rat has poor eyesight and is colorblind, but it can locate food with a very keen sense of smell. It also has excellent hearing and sensitive taste buds that can detect small amounts of poison in food. It will avoid any food that it senses is contaminated.

They are great climbers able to maneuver up some brick walls and swim across streams.  Amazingly, an adult rat can squeeze through a hole the size of a quarter. If it can squeeze its skull through a hole, its body can be elongated and get through, as well. Seal up holes using Xcluder, a product similar to steel wool, exept it won't ever rust.

Norway rats can spread diseases like typhoid and trichinosis, and they leave fecal pellets and urine stains which can cause salmonella poisoning. The bubonic plague is associated more with roof rats than with Norway rats, but Norway rats can be carriers of the disease.

Norway rats can also cause damage to houses and other manmade structures by building their extensive burrows under foundations undermining the structure and causing areas to sag. They do additional damage to wood with their incessant gnawing required to sharpen and refine their constantly growing teeth.

This rat species has a short lifespan, yet can increase its population rapidly under the right conditions. Capable of living up to three years, it often dies before its first birthday due to predators. However, its short gestation period and the fact that females are always œin season, keeps populations growing. A female Norway rat is capable of giving birth to six or more babies at a time. They give birth twenty one days after mating and can mate again in as little as two days, repeating this cycle five times during a single year. The cycle varies according to available resources and population overcrowding.

There is no guaranteed way to get rid of rats, but the best way is to outsmart them. The first step is to identify where they are coming from. Look for signs of gnawing, urine stains, fecal pellets, or actual sightings. Identify rodent runways if possible. Look for greasy smudges on the baseboards of walls or lines of treaded down grass along exterior foundation walls. Following a runway might lead you to the burrow entrance.

Try not to disturb surroundings or rearrange things. Any changes will make the rats more cautious and less likely to get caught in a trap. They usually do not stray much farther than fifty to one hundred and fifty feet from their nest, if possible, and repeatedly use pathways that they are familiar with and believe to be safe.

Now you know the basics and it's time to become Trapper John. Gather up your traps and use your new learned skills. Let's leave the rodent baits back at the hardware store to avoid poisoning your favorite pet, not to mention your favorite child. Besides, traps provide proof of your hunting successes in the form of a dead rodent body.

If your traps don't work you are most likely doing something wrong. I mean, rats are smart, but let's not give them too much credit. Do it right, even if you have to start from the top a couple of times. You will catch rats.

There are those of you who think you can make quick work using poisoned baits. Just keep in mind that the rats will be just as wary of new foods as they are of new rat traps. That said, there are many kinds of bait, but anticoagulants containing Warfarin are the most common. These slow acting baits are formulated to be accepted by the rats. If the rat doesn't eat enough to receive a lethal dose the first time it feeds, it will still come back for more before feeling ill side effects. You'll need to get rid of other food and water sources to encourage the rats to feed on your bait. Make sure that the bait you put out can only be accessed by the rats, and not pets or children. Covered and lockable bait stations will help keep other animals and children out. The station will also keep the bait fresher so the rats will be more likely to eat it. You will need to replace the bait after the rats have eaten it, or if the bait gets old or moldy. Fresh, clean food.

As my sixth grade math teacher use to say, œA rat in Tom's house may eat Tom's ice cream (The first letter of each word spells œarithmetic), but a rat in the house is certainly something most homeowners would wish to avoid. Even the cleanest, most secure homes can be invaded by a rat. The best you can do is to keep a clean, clutter-free house, seal any cracks you can find in the foundation and under thresholds and look for signs of exterior rodent activity before they chose your house as their new home.

Ask Rick A Question


Page generated in '.0.0225.' seconds.