How Big Can Rats Get? A Detailed Pet Rat Guide

IN THIS ARTICLE

• Rat Size Basics
• Exploring Rat Breeds and Sizes
• The Importance of Rat Habitats
• Caring for Your Pet Rat
• Key Takeaways: Nurturing Your Rat to Its Full Potential
• FAQs

Having a pet rat has become popular in recent years, but there’s still a ways to go before they overtake the cat and dog people. Rats are curious, intelligent, and playful by nature, so they can make perfect pets if you want a companion with low upkeep requirements. But how big can rats get once fully grown? Their size will depend on a few aspects, such as gender, breed, and background. Fancy rats (the most common pet rats) grow to between nine and 11 inches long, sans tail.

Read on to find out more about rat species and their respective sizes.

Rat Size Basics

Knowing how big can rats get will determine whether they’re the right pet for you. Their size will affect the choice of the cage, the number of pet rats you can keep, and their nutrition. You don’t want to keep them in a cage that doesn’t provide them enough space. A general rule is to buy a rat cage with 2.5 cubic feet per rat. Providing them with enough space is crucial for them to be able to exercise and play.

Rat size can vary significantly depending on the breed. Male rats usually outgrow female rats, but not by much, and it’s not easy to tell them apart by size alone. There are numerous breeds of rats, which also affect their original size. We’ll explain these to you in a bit. The environment where they live has a significant impact on their size. Rats living in their natural habitats will eat anything they find but have more opportunities to burn these calories. Domestic rats might get fat faster.

Female rats stop growing at around six to seven months old, while males can grow for another two months after that. Note that they reach sexual maturity at around two months, well before they’re considered fully grown. If you see a fully-grown rat in the pet store, it’s likely going to live for another year and a half, so it might not be the most worthwhile investment. Plus, rats are usually cuter when they’re little.

The Size Spectrum of Common Pet Rats

Adult rats can grow from nine to 11 inches in length. This doesn’t include their tail, which is an additional seven to nine inches long.

Regarding weight, male rats can weigh anywhere between 0.66 and 1.1 pounds. Female ones fall into the spectrum from 0.55 to 0.66 pounds. In general, a rat will need six months to grow fully. However, keep in mind that they’ll start reproducing after just five to eight weeks, which will leave you with numerous baby rats.

What Influences a Rat’s Size?

Rat size can vary significantly depending on the breed. Male rats usually outgrow female rats, but not by much, and it’s not easy to tell them apart by size alone. There are numerous breeds of rats, which also affect their original size.

There are numerous breeds of rats, which also affect their original size.

The environment where they live has a significant impact on their size. Rats living in their natural habitats will eat anything they find but have more opportunities to burn these calories. Domestic rats might get fat faster.

Exploring Rat Breeds and Sizes

There are several types of rats, and each has its characteristics. However, all domestic rats are a domesticated form of the common brown or Norwegian rat, classified as Rattus norvegicus domestica.

Fancy rats are the most common rat species you’ll encounter as a pet. They come in many colors and fur patterns, and are usually bred to maintain their short, smooth, and glossy fur, but there aren’t particular requirements on the size. These rats have an average size of around nine inches long for females and 11 inches for males (without the tail), with around 12 inches being their maximum.

Other varieties of pet rats, such as dumbo, hairless, tailless, or long-haired, don’t vary much in length from the “base” fancy version.

The length of your rat will primarily be influenced by the size of its cage, food quality, and genetics. A cage that’s too small might stunt their growth. Otherwise, breeders can subtly influence the size of rats by breeding larger or smaller rats together to try and maintain the intended size. However, even this doesn’t cause the size to shift significantly from the average.

In rare cases, a rat might display dwarfism. This is a recessive genetic mutation, so breeders need to “luck out” in getting one and continue interbreeding them. Dwarf rats are about five to seven inches long (without the tail), making them around the same size as a fancy pet mouse. Since they’re rarer and more demanding to breed (to maintain genetic diversity), they can cost much more than the average rat and you might not find a dwarf rat breeder locally.

Domestic Rat Breeds and Their Sizes

Fancy rats are the most common rat species you’ll encounter as a pet. These rats have an average size of around nine inches long for females and 11 inches for males (without the tail), with around 12 inches being their maximum. Other varieties of pet rats, such as dumbo, hairless, tailless, or long-haired, don’t vary much in length from the “base” fancy version.

World Record Sizes for Rats

The largest rat species in size in the world is the Gambian pouched rat. It’s nearly three feet long from nose to tail and can weigh up to three pounds. This makes the Gambian rat three times larger than the domesticated brown rat. However, it’s illegal to keep them as pets in North America.

The Importance of Rat Habitats

Rats are very active animals and need their space to play and explore. Closing them into cages smaller than what fits their needs will limit their activities. This can make them obese and depressed, leading to health problems. As a result, this will increase vet expenses and shorten their life span. Choosing the right cage is one of the most essential steps of rat care.

On Quality Cage’s website, you can find a wide variety of cages. Keep in mind that the bars should be relatively dense. This lack of spacing is vital to prevent your rat from escaping or getting stuck while you sleep.

The Role of Habitat in Rat Growth and Health

Rats are active animals that need space to play and run. Being unable to help them to fulfill these needs can lead to depression and physical health problems, such as getting overweight. They need enough space to both sleep and have their toys inside the cage. On Quality Cage’s website, you can find a wide variety of cages, which can fit any rat’s needs and your budget. They have a selection of finely crafted cages, which can be a home to either a chinchilla or a rat.

Choosing the Right Cage for Your Rat’s Size

A general rule is to buy a rat cage with 2.5 cubic feet per rat. Providing them with enough space is crucial for them to be able to exercise and play. On Quality Cage’s website, you can find a wide range of cages in all sizes, which can accommodate both a single, as well as rats in pairs.

Caring for Your Pet Rat

Providing your pet rat with the right cage isn’t the only thing that will make them happy and healthy. They’re active animals that need toys and mental stimulation. Get them a cage that will fit both its toys and proper bedding. Another important factor when taking care of your rat, is nutrition. Although rats that live in the wild eat whatever they find, your rat does have nutritional needs. Make sure you get rat pellets that fulfill their daily dose of nutrients and include fresh fruits and vegetables in their diet.

Not enough room to exercise and a poor diet can lead to your pet being obese, which will further lead to other health problems.

Dietary Requirements for Healthy Growth

One of the health issues that rats face is obesity. You have to keep their diet rich and versatile in order to keep them healthy and fit. The ideal rat food is rat pellets, as it’s rich in nutrients. It’s advised to give your rats fresh fruit and vegetables. A treat isn’t considered healthy, but it’s a good reward for them occasionally, especially when they’ve learned a new trick.

Exercise and Environmental Enrichment

Since rats are active and curious animals, you can’t just put them in an empty cage and expect them to be happy. They need exercise and stimulation. Luckily, Quality Cage has a rich assortment of accessories, which include wheels, toys, hammocks, etc. There are a lot of rat supplies that you can buy on their website, so make sure to take a look.

Key Takeaways: Nurturing Your Rat to Its Full Potential

To make sure you know what you’re getting yourself into when buying a rat, you should know how big your rat can get. On average, adult rats can grow from nine to 11 inches in length, with the tail being roughly the same length.

When buying a rat cage, ensure it suits your future pet’s size and makes it feel comfortable. If rats don’t get their daily dose of exercise, they might become obese. Giving them a nutrient-rich diet is another crucial factor in keeping them healthy and living longer.

Whichever supplies you may need for your rat, regardless of its breed or size, Quality Cage is your destination. You can find anything on their website, from cages to smaller accessories.

FAQs

What is the biggest size of a rat?

The most giant rat is the Gambian pouched rat, which is about the size of a cat. However, it’s illegal to keep these as pets in North America.

How big do NYC rats get?

The rats on the streets of NYC are usually wild brown rats (Norway rat, Rattus norvegicus). They typically grow up to eight to 10 inches long, and can weigh around a pound and a half.

Can rats get as big as cats?

The Gambian pouched rat is a giant rat from West Africa that can be three feet long and weigh three pounds. They are not legal as pets. Most common pet rats fall short of a foot long.

How big can a house rat get?

A wild house rat (i.e. one that isn’t a pet) is usually smaller than the pet varieties since they get hunted or die before reaching their full size. They rarely reach over 10 inches long, tail excluded.

Questions?

Have Questions About Rat Sizes?

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