How large do rats get?

Most rats weigh in at around two pounds in terms of weight, with the average rat being around half a pound to a pound. Smaller rats tend to fall victim to traps much more frequently than their larger counterparts, but the larger rats aren't entirely safe. Dogs seem to get their teeth on those more often than not. That's just two small insights into the natural predators in a rat's world. I bet you thought they didn't have any.

In a 2014 study, it was reported that there were around two million rats in New York City alone, and most of them are around 30 to 40 cm in length. The biggest of them will grown to about two feet, and, back in New York City again, there have even been reports of some rats rarely weighing in lover two feet, and also over three pounds too. Thankfully, this is a very rare case.

There seem to be stories each year, on both sides of the Atlantic, of rats getting bigger and bigger. Some places even refer to these larger rats as “super size rats”, and it seems to be a trend that's on the rise too. Maybe we're feeding them more, being more careless with our waste? Perhaps we're opening our homes to more of them, not taking care of our own bricks and mortar, ensuring all home repairs are done and maintenance is kept up to scratch? One thing is for sure - their population isn't dwindling. It doesn't seem to ever dwindle. They just make their way around the world, taking over where humans do, cleaning up our waste and leaving a trail of destruction and disease in their wake.

How big do rats get? It's not the size of the rat that you should worry about. It's the amount of damage one rat will do to your home, and the disease it can spread too. One rat will mean two rats soon, and then ten rats when the babies come along. Be smart - do your home repairs, and if you find that you have rats already, do something about it. A rat might not be very big, but the problem sure is.

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Everyone has heard stories of the giant sewer rats that are present in the subterranean big cities. Are they true? There have been many pictures taken where rats appear to be huge but are they just a hoax? Most of the time when humans see rats, they are almost always smaller than a kitten. There are many factors that play into the size of a rat, and these vary from region to region. Continue reading this article for a look into the size of each species of rat found in North America.

Norway Rat

The most common rat in North America is hands-down the Norway rat. This is the one that is seen rummaging around for food in big city alleys, eating trash from your garbage can, and burrowing in tunnels. In North America, the Norway rat, or the brown rat, is the largest species of rat. On average, the brown rat is around 15-20 inches long, with the tail included. They are differentiated from other rats by their short ears. 

Roof Rat

The roof rat is most common in coastal areas or other humid climates, though they can live in cooler climates if need be. These rats are also known as the black rat or ship rat, in addition to being called roof rats. They commonly migrate from areas on ships and live in many people’s roofs in tropical climates. Roof rats are anywhere from 5-7 inches long, with a tail that can get close to 8 inches long. They can be distinguished from other rats by their long ears. 


The woodrat, or packrat, is common in the Western United States, in addition to Western Canada as well. These creatures are 7-8 inches long, in addition to a 7-8 inch tail as well. You can easily tell woodrats apart from other rats, as they have a very long and skinny tail, big ears, and big, round eyes that are very black in color. These critters can get really big in certain areas, and remain smaller in others. 

Marsh Rice Rat

The marsh rice rat is found primarily in the Gulf Coast and all around the Florida Keys. They usually go as far west as about Texas and stay in the Southeastern United States. Marsh rice rats are smaller-sized rats. Their total length, with the tail included, is up to a foot long. They can be easily identified because of their smaller length and more-round body. These can often be confused with mice. 

Biggest of All Rats

The biggest rat in the world is a hotly disputed topic, as there have been many claims. There are several factors that contribute to a rat being very large. One of the most important ones is species, followed by food sources and competition. One of the biggest recorded rats of all time was a rat found dead in the United Kingdom by a children’s playground. The rat was four feet long and weighed 25 pounds! Needless to say, this was a mutant rat and is most certainly not the norm for rats anywhere in the world. All in all, except in rare cases, rats remain at their standard size which was discussed in this article.