Do Beavers Lay Eggs? No! (Here’s What They Do)

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Have you ever heard someone say they’re as busy as a beaver building a new dam? Beavers are known for their hardworking and dedicated nature.

But what isn’t as well known is the beavers’ method of giving birth to their young.

Beavers don’t lay eggs; they are placental mammals, so their litters of four to eight kits gestate in their mother’s womb and are born once they’re fully developed. Beavers typically mate in the winter months and have a three-month pregnancy on average. Kits are born with all of their fur, erupted incisor teeth, and open eyes.

Read on to learn about the way beavers give birth to their young, how they reproduce, the length of their pregnancy, and what happens if a beaver’s mate dies. We’ll also discuss the two mammals that do lay eggs.

Do Beavers Give Birth Or Lay Eggs?

Beavers are a type of placental mammal. This means that their young develop in the womb, rather than in an egg. 

Instead of laying eggs, beavers give birth to live offspring once it has gestated and fully developed.

How Do Beavers Reproduce?

Beavers reproduce through sexual intercourse. They reach sexual maturity when they are two or three years old, and their entire lifespan is about 10 years, although some beavers live much longer, particularly if they live in captivity

They typically mate during the winter months, between November and March. After a three-month gestation period, beavers’ offspring are most frequently born in April, May, or June. 

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Female beavers give birth to one litter each year, and a litter usually consists of one to four kits. However, it’s possible for up to eight kits to be in a single litter.

Baby beavers are born with erupted incisor teeth, open eyes, and all of their fur. For the first one or two years of their lives, they continue to live with their parents. After that, they leave to find mates and start a family of their own.

How Long Are Beavers Pregnant?

After mating during the winter months, beavers are pregnant for an average of three months, but this can vary by the type of beaver.

For example, American beavers gestate for 105 to 107 days, which is about three and a half months. Meanwhile, Eurasian beavers gestate for 60 to 128 days. This is a range of two to just over four months.

American beaver kits weigh between nine and 21 ounces, and Eurasian beaver kits usually weigh eight to 22 ounces.

After giving birth, American beavers nurse their babies for around two weeks, while Eurasian beavers nurse for an average of six weeks.

Baby beavers live in a lodge with their parents, who are monogamous, as well as the other kits in their litter and the yearlings that were born the year before. 

What Happens If A Beaver’s Mate Dies?

Beavers are extremely family-oriented and are known for being monogamous. In most cases, beavers mate for life. They can experience up to 20 years of life together, depending on their lifespan; the oldest beaver on record lived for 30 years.

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Some sources state that if one parent dies, the other never mates again.

Other sources report that if one of the beavers in a pair passes away, the other will look for a new mate.

Do Other Mammals Lay Eggs?

Placental mammals are not the only kind of mammals. There are also monotreme mammals and marsupial mammals. These three groups of mammals are classified by the ways they give birth to their offspring.

In general, mammals are warm-blooded animals. They’re covered in fur and live in nearly every type of environment across the globe, ranging from tropical areas to polar regions.

Mammals have existed for over 200 million years. They first started to show up during the dinosaur era. At that time, they were much smaller in size.

Once the dinosaurs went extinct about 65 million years ago, mammals continued to evolve, and many of them became much larger.

Monotreme mammals are the most ancient type of mammal. They lay eggs, and once their offspring hatches from the eggs, they feed on their mother’s milk like all other mammals. 

The difference is that rather than coming from teats, the milk is secreted from pores on the mother’s belly.

There are only two types of monotreme mammals around today. They are the platypus and the spiny anteater. No other mammals lay eggs. 

Marsupial mammals give birth to offspring before it is fully formed. Then, the offspring grows within a pouch located on its mother’s belly. From this pouch, the offspring can drink its mother’s milk and continue to grow and develop. 

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Kangaroos, opossums, koalas, wombats, and sugar gliders are all examples of marsupial mammals, although there are many more.

Placental mammals make up most of the mammals that exist today. Offspring develop inside their mother’s placenta, getting nourishment from their mother’s diet through the umbilical cord. Mothers give live birth to their offspring once they’re fully developed.

Beavers, cats, dogs, horses, elephants, and many other animals are all placental mammals.

Which Mammals Lay Eggs?

Today, the planet only houses two types of egg-laying or monotreme mammals.

These are the echidna, better known as the spiny anteater, and the duck-billed platypus. Both of these animals live in Australia, Tasmania, and New Guinea. 

Interestingly, the platypus and anteater share multiple characteristics with reptiles. For example, they have a lower body temperature than other mammals. In addition, they only have one opening for both eggs and waste.


Beavers do not lay eggs. Instead, female beavers give birth to live young after they develop inside her womb. Beavers are known as placental mammals, meaning that they have a placenta where offspring develop and an umbilical cord that provides nutrients to their kits as they grow.

The mating season for beavers is in the winter, and they usually have a three-month pregnancy. Kits are born in litters consisting of four to eight baby beavers. When they’re born, their eyes are open, their incisor teeth have erupted, and they’ve grown all of their fur.

Learn More About Beavers:

  1. Do Beavers Hibernate or Migrate In Winter?
  2. Can Beavers Climb Trees?
  3. What Do Beavers Eat?
  4. Do Beavers Eat Fish?
  5. Do Beavers Eat Meat?

James Ball

James has had a lifelong passion for animals and nature, tracing back to his childhood where he first began fostering intimate knowledge and connection with pet frogs and snakes. He has since honed this interest into a career as a trained Wildlife Biologist, specializing in Biogeography, sustainability and conservation. In addition to his professional pursuits, James maintains an active lifestyle, regularly indulging in outdoor activities such as hiking, and musical pursuits like playing piano and swimming.

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