Average Litter Size

Written by Sarah Psaradelis
Published: April 15, 2023
Image Credit © Kassia Marie Ott/Shutterstock.com


The average number of offspring produced by an animal during one birth.


This phrase refers to the normal or expected number of offspring an animal will produce during a single birth. This number can vary depending on the species of animal since not all animals will produce multiple offspring in a litter and instead only give birth to one. A litter of offspring is common amongst mammals that give live birth, and they are expected to have more than one offspring. The litter of offspring will be produced from the same female animal during a single birth, and the offspring from the same litter are referred to as littermates. Certain factors can influence the average litter size, such as genetics, uterus type, and the duration of the gestation period.

A mother cat nursing a litter of kittens
Cats have an average litter of 3-5 kittens.


Calculating an Animal’s Average Litter Size

The maximum size of an animal’s litter depends on the number of teats they have. However, the average litter size is about half the number of nipples the animal has, varying by one or two. If the animal only has 12 nipples, then the average litter size for that specific animal will be around 6 offspring. There are animals that are an exception to this rule, and their average litter size may exceed or match the number of treats that they have. The naked mole rat is a good example of an animal that has an average litter size of 11 pups while having approximately 12 nipples.

A female rat snuggling with her many babies against a white background
Female rats can have from 8 to 18 pups per litter.

©Maryia Karneyenka/Shutterstock.com

Factors That Affect The Average Litter Size

There are certain factors that can influence the average size of the litter, such as the:

  • Species of animal
  • Genetics
  • Gestation period
  • Age
  • Number of teats
  • Type of uterus
  • Overall health

Aside from the genetic factor, there are many environmental and nutritional factors that can affect the animals’ average litter size.

Certain species of animals like the tenrec naturally have a larger average litter size. This is mainly due to the females having 29 nipples, with an average litter size of 13 to 20 offspring. Sometimes, the tenrec can have up to 32 offspring during a single birth. Whereas other species of animals may have fewer nipples and do not need to have such a high number of offspring. Genetics plays a role in the average litter size for a particular species of animal. For example, a dog with smaller gene pools may have a smaller litter in comparison to dogs with larger gene pools.

Age can affect the size of the mother litter, and it is common for some young and first-time mothers to produce smaller litter. However, as the mother nears her optimal breeding age, the litter may become smaller too. If the animal were to produce multiple offspring, the uterus would need to accommodate the growth of multiple fetuses. This means that the uterus must handle the capacity of offspring the mother will carry during pregnancy.

A family of bat-eared fox pups at the entrance to their den
Bat-eared foxes have three to six kits per litter.

©Etienne Outram/Shutterstock.com

Average Litter Size of Common Animals

Animal:Average Litter Size:
Dogs4 to 6 pups
Cats3 to 5 kittens
Hamsters6 to 7 pups
Rabbits6 to 10 kittens
Rats6 to 11 pups
Hedgehogs4 to 6 hoglets
Wild boar4 to 6 piglets
Bear1 to 3 cubs
Beaver4 to 5 kits
Tenrec13 to 20 offspring
Prairie vole4 pups
Opossum6 to 8 joey’s

How Animals Have Multiple Offspring

It is normal for many species of animals to produce multiple offspring at a time.  Litter-bearing animals will always have more than one offspring at a time because the female releases multiple eggs. These eggs will produce multiple embryos once they have been fertilized, but in some cases, the mother will only give birth to one baby even if it is normal for the species to have multiple offspring.

Mother dog nursing her puppies
Dogs have an average of 4 to 6 puppies.

©Anna Hoychuk/Shutterstock.com

Share this post on:
About the Author

I am an animal lover that not only enjoys owning and getting to care for them, but also writing about them! I currently own fish, a crested gecko, an adorable hamster, fancy rats, and a docile tarantula. Writing has become my passion and I enjoy writing about the animals I love so dearly so that I can share my knowledge and expertise in my work.