You may think we’ll be talking about all the rodents in the wild and the dark spaces of your house, but we’re not. That may be too broad and too large to cover! We’re talking about the ordinary house mouse, Mus musculus, and the brown rat, Rattus norvegicus. These are the most common rodents people have as pets or pests in their homes.

These rodents can be annoying and too destructive to have around. They gnaw on almost anything, even stuff that may have sentimental value to you! But did you know that these creatures have a very rapid and short gestation period? No wonder how they endlessly multiply inside your home.

Let’s learn more about the gestation period of these common rodents.

The gestation period of rodents

The gestation period is the time between conception and birth when a baby develops inside its mother’s womb. For rodents, the average gestation time can vary depending on the species and what family they belong to. 

For the house mouse, the average gestation length is 19-21 days. For the brown rat, it’s 21-23 days. That’s a short pregnancy- safe to say you can have several rodents every month! 

Pregnant rodents are called dams, and the process of giving birth is called parturition. At the end of the gestation period, the dam will start to build a nest out of soft materials like shredded paper or fabric. The dam will also pull its fur to line the nest. 

Their Mating season

Unlike other rodents in the wild, mice and rats do not have a breeding season. They mate all their lives whenever they find the chance. However, they still have their “busiest” mating cycle. It happens in spring, from March until June.

Generally, these sneaky rodents avoid the cold, harsh climate of winter. If they can, they’ll try to find a way into your house to escape the cold and take advantage of your food stash! But during their mating season, they become more active and reproduce more. This happens to both indoor and outdoor mice and rats. 

Rodent’s mating behavior

Various research cases have been done to observe the mating behavior of mice. Male mice are known to chase female mice when they’re in heat.

Female rats are also polygamous. They breed all year round but fewer during the fall and winter seasons. The female will mate with as many males as possible until she’s pregnant. After that, she becomes aggressive and will fight other females who come near her. 

For rats, mating usually begins with an inspection of the female rat’s face and body. After that, the male will start to groom her. If the female is okay with it, she’ll allow him to mount her. 

After successful mating, the female will lick herself clean. This is important because she needs to remove the male’s pheromones from her body. Otherwise, other males will continue to harass her.

Rodents’ nesting habit

As mentioned earlier, female rodents will start to build a nest at the end of their gestation period. The nests provide a warm and safe place for the dam to give birth. The nest also provides insulation against cold weather and protects newborns from predators. 

When building a nest, the dam will use its teeth to shred a soft nesting material like paper or fabric. She’ll also pull her fur to line the nest. The nest is usually built in a hidden place, like behind a piece of furniture, crawl space, or in a hole in the wall. 

How many pups do rodents have?

The number of offspring a rodent can have varies depending on the species. For instance, a house mouse can have six pups per litter. Female adults can have many litters each year! They’re estimated to have new babies at least every three weeks.

On the other hand, brown rats can have three times as much as mice. The average litter size for the brown rat is 8 to 18! 

Rodent’s pups

Like other rodent pups, baby rats are born deaf, blind, and naked. Their eyes will open after about two weeks, and they’ll start to grow fur at around three weeks old. At this point, they’re also able to eat solid food. 

Mice pups develop changes a little bit faster than rats. Their eyes open after only one week, and they start to grow fur at around 10 days old. By the time they’re three weeks old, they’re fully developed and ready to leave the nest. 

Rodent Weaning

Weaning occurs with the pup’s mother’s milk at around four to six weeks old. After development, they’re on their own and will start to find mates. Four weeks after birth, baby mice are weaned, at which point they can be raised on their own. Males and females can mate to have more children 8 weeks after birth.

For rats, they become weaned a week later. Then, they become sexually mature at 7 weeks old.

More About Rodents

Rodents are not just rats, mice, and all the annoying gnawing creatures in your house. There are over 1,500 species of rodents! They come in all shapes, sizes, and behaviors. The largest rodent is the capybara, which can grow to 150 pounds! The smallest is the pygmy rice rat, only about 3 to 6 inches long. 

Some rodents live in the water, like beavers and nutrias. Some can fly, like the flying squirrel. Others live in the trees, like the acouchi. Some rodents, like hamsters, lemmings, and gerbils, are even kept as pets. But before you think about it, note that keeping some of them as pets is illegal in some states. This includes chipmunks, squirrels, beavers, and voles.

As well as the opossum, kangaroo rat, shrew mole, vole, pocket gopher, deer mice, ground squirrel, chipmunk, marmot, gerbil, and prairie dog.

Did you know that porcupines are rodents too? And contrary to popular belief, they cannot shoot their quills. The quills are barbed, so when they lodge in an attacker, they work themselves further in as the animal tries to remove them. Ouch!

Need Help With Rodents On Your Property? Call Us Now!

If you have rodent problems on your property, don’t wait to take action. These creatures can multiply quickly, cause severe damage to your home or business, and pose health problems. 

We have the experience and expertise to eliminate your rodent problem for good. 

Call AAAC Wildlife Removal today!

Conclusion

No wonder mice and rats are one of the most common pests in the world. With their rapid gestation and multiple pregnancies in a single year, it’s hardly surprising that these furry creatures can quickly take over your property if you’re not careful.

While some people view rodents as cute and cuddly creatures, others see them as nothing more than dirty animals that carry disease. Regardless of how you feel about them, taking action is crucial if you have a rodent problem on your hands.

To learn more about rodent gestation and their reproductive capabilities, click here: rodent gestation.