Welcome to Rodents 101

Rodents are the most significant group of mammals found on this earth.

Their ability to affect this world both numerically and economically has been evident for centuries and they have spread throughout the globe, inhabiting every continent except Antarctica.

This site is a resource to help you get to know the many rodents throughout our world.

Throughout this site, we will attempt to cover every species of rodent there is in a way that explains them in an everyday way.

What are Rodents?

  • There are 2,277 species of rodents across 431 genus in 28 families which are listed below.
  • They account for more than 40% of all mammals.
  • They are found in various places all across the world, in all kinds of habitat, with all kinds of characteristics and habits.
  • They are spread over all continents apart from Antarctica.
  • They live in all habitats except for seas and oceans.
  • The are significant members of the food chain being prey and predators to many different species of animal.
  • The word rodent stems from the Latin ‘rodere’ which means to gnaw and ‘roedor’ which is the Spanish for rodent and is an animal who ‘roe’ which means to gnaw.
  • Some rodents have developed as pests because of their amazing adaptability to the human environment taking advantage of our work and enjoying the benefits of the environment that we live.
  • Their main characteristics are that they have different shaped skulls and have a particular arrangement of the jaw musculature, which is the the system or arrangement of muscles around the jaw.
  • They manage to survive by reproducing in significant numbers which mean they have a big impact on our world from those that help our environment to those that are pests to those that are food for others.
  • Amongst Rodents, pregnancies are very short which allows them to spread across habitats that they happen to be in.
  • The first fossil record of mammals that are rodent like is 66 million years old which is just after non-avian dinosaurs were extinct. They appear towards the end of the Paleocene epoch and their ancestry is found in a grouip of fossil mamals named the Mimotinids or the Anagalids.
  • They can vary in size from the very tiny Africa Pygmy Mouse which is 6cm small to the largest living rodent, the Capybara weighing in at 65kg to the largest known rodent which is the now extinct Josephoartigasia Monesi, weighing in at about 1,000 kg.
  • All Rodents use their sharp incisors to gnaw wood, break into food, and help defend themselves against predators
  • Despite the fact that they are such a diverse order of species, they do share common features in that they have a single pair of incisors in each of their jaw’s, and their incisors grow continuously throughout their lives.
  • The first fossil record of mammals that are rodent like is 66 million years old which is just after non-avian dinosaurs were extinct.

Taxonomic Rank of Rodents

Rodents have the following taxonomic rank;

They belong to the animal kingdom (animalia)

The Chordata Phylum

The class of Mammalia

The super order Euarchontoglires

The order Rodentia.

The order is then divided into the following sub orders and families to categorise each rodent.

Just click on each family to find out more about the rodents in that particular family. If you want to find a particular rodent then use the search tool in the top right hand corner.


rodentsCtenodactylidae: They are Comb Rats or Gundis who are found in Africa. There five species in the family and were first discovered by scientists in 1774.

Diatomyidae: Are represented by one living species, the rest are extinct. They are characterised by having cheek teeth with four roots part from the first.

rodent factsBathyergidae: They are mole rats otherwise known as the blesmols and are burrowing rodents.


rodentHystricidae: They are old world porcupines that are known for their spiny coverings. They differ from new world porcupines which belong to the family Erethizontidae.

Petromuridae: The only living genus is the Dassie Rat otherwise known as the Rock Rat.

rodentThryonomyidae: Known as Cane Rats which are found in sub-saharan Africa.


rodentsErethizontidae: The New World Porcupines are different from Old world porcupines as they are much larger. They live throughout North America and some areas of South America.

nature of rodentsChinchillidae: Consisiting of Chinichillas, Viscachas and other extinct relatives, they are found throughout south and west South America.

Dinomyidae: They have only one living species, the rest are now extinct. They have the largest rodents known and ranked.

Caviidae: Native to South America, they contain rodents such as wild and domestic guinea pigs and the Capybara.

Dasyproctidae: Containing acouchis and agoutis, the rodents in this family are native to South America, are herbivores and will reside in burrows.

Cuniculidae: Found throughout Central and South America, the Paca is the only member of this family.

Ctenomyidae: The Tuco-tuco is the only rodent of this family, of which there are 60 species, and are known for their ‘tuc-tuc’ sound that they make. They are found in parts of South America.

Octodontidae: Found in South West South America, they are medium sized rodents and are known for the pattern of their teeth which resembles the figure 8. The best known is the Degu.

Abrocomidae: Chinchiliones or Chinchilla Rats are found in this family and are different from Chinchillas. They are found in the Andes in South America.

Echimyidae: This family contains the Neotropical Spiny Rats which are found throughout South and Central America.

Capromyidae: This family contains the Hutia which are found throughout the Caribbean Islands.

Heptaxodontidae: This is the family of the Giant Hutia which are now extinct. They were known as very large rodents.

Myocastoridae: The family of the Coypu also known as the River Rat or the Nutria. They were originally from South America, but are know found in Africa, Asia, Europe, and North America.



Anomaluridae: Found in Central Africa, they are Scaly-Tailed Squirrels or Anomaluresof which there are seven extant species.

Pedetidae: The Springhare and the Anomalure is found in Central and South Africa.


Aplodontidae: The mountain beaver is found in North America and is different from the North America which is from the family Castoridae. They are the largest rodent in North America.

Sciuridae: Made up of Squirrels from across Africa, Eurasia, North and South America, and Australia. They also contain Prairie Dogs, Flying Squirrels and Marmots.

Gliridae: Consists of the various species of the Dormouse found throughout Asia, Africa, and Europe.

Suborder Castorimorpha

Castoridae: Contains one single genus, Castor which contains two living species of beavers and are medium-sized mammals.

Geomyidae: Pocket Gophers, otherwise known as Gophers are rodents that burrows found throughout North and Central America.

Heteromyidae: Made up of Kangaroo rats and mice and also Pocket Mice. They are found in North West America and some parts of South Americ


Dipodidae: They are rodents found throughout the Northern Hemisphere and are small to medium sized and all capable of jumping.

Platacanthomyidae: They are made up of Oriental Dormice found throughout south east asia.

Spalacidae: The spalacids are found in East Asia, parts of Africa, the Middle East and South East Europe.

Calomyscidae: They are mouse-like hamsters found throughout the middle east, Persia and Mid-Asia.

All images courtesy of wikipedia

Nesomyidae: They are small to medium rodents found throughout Africa and Madagascar and are known for climbing trees and burrowing.

rodent factsCricetidae: They are small mammals and are the second largest family of mammals with species across the Americas, Asia and Europe. It includes Lemmings, Voles Hamsters, Rats and Mice.

rodentMuridae: The Murids are small mammals with slender bodies, scaled tails, snouts that are pointed and whiskers and are the largest family of mammals with species found across the world including Gerbils, Rats and Mice.

My name is Chris Perkins and I am the main contributor to this site, please do contact me using the contact form if you have any queries, questions, feedback, complaints, etc.


Rodents 101 is a resource written to educate and inform. Although we edit this site for accuracy we cannot guarantee all information on the site and it may not include all the latest scientific information about organisms we describe. Whilst we provide references to websites and books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.


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