Few people have been able to see baby mice, except perhaps those who breed these animals. But breeders claim that success in this fascinating activity is impossible without certain knowledge about the reproduction of rodents. Therefore, we will find out how many times a year a mouse can give birth without harm to health, how many cubs there are in one litter, and what kind of care they need.
Puberty
Mice reach maturity quite early. In females, the first estrus begins at the age of 30-35 days. The males' readiness to mate is indicated by the descent of the testes into the scrotum. This occurs around the 5th to 7th week of life.
Males can breed all year round. The ability to reproduce in males remains until old age, provided that they are kept in good conditions and receive adequate nutrition.
Despite such early puberty, it is not advisable for a female to give birth to cubs after her first heat. Her body continues to form and is not yet ready for reproduction. Complications may occur during pregnancy or childbirth. For this reason, rodentologists recommend waiting for at least 3 months with the first mating of a female.
How is it different from an adult mouse?
A rat reaches its maximum size by one year. The appearance of a rat at the age of one month is similar in appearance to an adult mouse. People who do not know the difference between baby rats and adult voles use the wrong control tactics and therefore cannot get rid of pests.
The easiest way to identify a mammal is by the track it leaves on damp ground. A rat's feet are webbed, so a print with widely spaced toes and folds between them will be visible on the ground. Rat tracks in the snow are clearly visible.
Interesting!
The size of a month-old baby rat's paw is no different from the size of an adult mouse's foot.
Animals also move differently. The mouse minces and the rat jumps. If the tracks on the ground are located close to each other, then there was a hole running through here.
Phases of the sexual cycle
The duration of the sexual cycle in mice is 5-9 days. Its duration largely depends on the living conditions of the female. An important role is played by the health of the mouse and its physiological characteristics.
Phases of the reproductive cycle in mice:
- Proestrus (precursor). A period of rapid growth of follicles that produce estrogens. Under the influence of hormones, blood supply to the genital organs increases. Cells of the mucous membrane of the vagina and cervix secrete secretions. The upper layer of the mucous membrane becomes keratinized.
- Estrus (heat). The sexual arousal phase, which lasts 10-18 hours in mice. Mucus secretion increases, the cervix relaxes. During this period, the mature follicle ruptures and an egg is released. The female strives to mate and allows the male to mate.
- Metestrus, or post-estrus. At this stage of the reproductive cycle, the cells of the disintegrated follicle separate, then the corpus luteum is formed from them. The cervix closes and blood flow to the genitals decreases. The average duration of this phase is 24-36 hours.
- Diestrus is a state of rest. This phase lasts 2.5-3 days. At this time, the corpus luteum dominates. The glands of the uterus are active, the cervix is closed. The genitals are pale, and almost no mucous secretion is produced.
Younger age
Starting from the fourth day, the development of little rat pups occurs at a rapid pace.
- 4th day the ears open, the pups begin to distinguish sounds and hear rustling sounds;
- 6th body is covered with soft dark fluff;
- On the 8th, teeth emerge, except for the main incisors.
After 10 days of life, the pups become active. They crawl well and master the terrain. If these are pets, they should be handled more often so that the animals grow up tame. However, during the game they should not be left unattended, since coordination of movements is not yet developed, the kids can fall to the floor from a table, any height.
How does mating happen?
Males are ready to breed at any time, but they become especially interested in mating during the female's estrus. At home, mice of different sexes are kept separately. A female is placed with a male only for mating. When rodents live together permanently, the mouse gives birth to one litter after another. This will negatively affect her health.
A female can only give birth to cubs if she meets a male during estrus. During this short period of time, her behavior changes. In the presence of a male, she raises the back of her body and freezes in this position for several seconds.
The acquaintance of opposite-sex individuals does not last long. The male then approaches from behind and performs sexual intercourse. Coitus alone is not enough to conceive babies. It is advisable to leave the couple together for a day to allow several mating attempts to occur. Then the probability of the mouse having babies will increase significantly. In the intervals between mating games, rodents eat, drink water and wash their fur.
Attention! The female should be placed in a separate cage the day after her meeting with the male. She needs rest while bearing her cubs.
In the wild, rodents breed only in the warm season. House mice breed all year round. The animal owner must control this process. Rodentologists recommend mating a female with a male 4-5 times a year. Due to frequent pregnancies and childbirths, immunity decreases and the risk of stillbirth or non-viable babies increases.
When can you pick up baby rats?
Touching baby rats immediately after birth is highly discouraged! The mother can eat a baby with a human smell, and there is also a chance of accidentally damaging the newborn’s thin bones.
Towards the end of the second week of life, you can briefly remove the newborns from the nest in the absence of the female, examine the pups and determine the sex of the animals. It is advisable to do this while wearing medical gloves or thoroughly washed hands so that the female does not abandon the brood.
From the end of the second week, you can take the babies out of the cage, often in the presence of the mother, so that the rat trusts you and does not worry about the children. Rats at this age are unusually nimble and inquisitive, while the female is on a walk every day, it is advisable to accustom the rats to friendly human communication: carefully carry in two palms, stroke, talk in a gentle voice, wear in the sleeve and in the bosom. Wary tiny animals quickly get used to people and begin to trust them.
IMPORTANT. Lack of active close communication with a person at a young age can make a pet fearful or aggressive towards humans.
Pregnancy
Pregnancy in mice is indicated by the absence of another estrus. An attentive owner will definitely notice changes in the behavior of the rodent while bearing cubs. Some animals become calmer, others, on the contrary, become irritable or even aggressive.
Until almost the middle of pregnancy, it is impossible to determine that the mouse is carrying cubs in the womb. The rodent looks normal except for the fact that its appetite is slightly increased. The mouse walks smoothly and carefully. Motor activity decreases slightly. In the second half of the term, the abdomen increases in size. Shortly before birth, you can feel the fruit inside.
During pregnancy, mice experience toxicosis:
- the female loses her appetite;
- looks lethargic;
- eyelids drooping;
- drool flows from the mouth;
- sometimes there are cramps.
Important! Toxicosis cannot be treated. A mouse that bears offspring needs to be provided with complete rest, since the main cause of this pathology is stress.
How many babies does a mouse carry?
The gestation period in mice lasts 18-24 days. The duration of gestation depends on how many cubs are in the womb. The greater the number of pups, the faster the birth will begin. The length of gestation can also be affected by the conditions under which the rodent is kept.
In a favorable environment and with good nutrition, the mouse waits 20-22 days for the birth of its cubs.
Caring for a pregnant mouse
From the home of the mouse that carries the cubs, everything unnecessary is removed - the wheel, the tunnels. Access to the second level is limited.
About 10-12 days before giving birth, the mouse begins to build a nest. To do this, she will need pieces of fabric, napkins and paper. The rodent carries all this into the house. If until now the animal did not have a private place in the cage, the owner must equip it. It is there that the mouse gives birth to her pups and takes care of them.
The temperature and humidity in the room should remain approximately the same level. Do not disturb the mouse unnecessarily. Even cleaning the cage during pregnancy is done less often than usual. No noise or contact with other animals is allowed.
Despite the fact that the mouse needs rest, motor activity is not limited. The expectant mother is not prohibited from walking outside the cage, but only under the supervision of the owner.
5-6 days before the birth of the cubs, you need to do a general cleaning of the mouse’s home. All equipment and trays are thoroughly washed and disinfected with boiling water. It is better not to touch the nest if the female has already managed to equip it. If the male was still in the cage with the pregnant mouse, he should be removed.
If this is not done, he can impregnate the female within a few hours after birth.
Feeding
In the first half of the gestation period, the mouse's daily food intake is increased by a third, and in the second half, it is doubled. In addition to the grain mixture, the female should receive vegetables, fruits and fresh herbs. Since calcium and protein are needed for the development of cubs, low-fat cottage cheese, eggs and milk are introduced into the diet.
A glucose solution is added to drinking water. There should be a lick stone in the cage, with the help of which the mouse satisfies the increased need for minerals.
Interesting facts about animals
Regardless of size, adult rodents of both species can have a litter of more than 15 or as few as two or three cubs. On average, one litter can contain about 9 cubs.
An interesting fact is that these two types of rodents cannot interbreed. Moreover, they are enemies.
Another curious factor that distinguishes the animals from each other is that the mental abilities of rats are head and shoulders above the abilities of their smaller brothers. Scientists have discovered that they are endowed with abstract thinking, thus putting rats on the same level as us, the only creatures that have this ability.
They will never live where they are in danger; before moving in, they will definitely study the upcoming living conditions. And finally, the rat community lives according to strict laws, strictly observing the hierarchy.
Mice are endowed with intelligence to a much lesser extent . Therefore, the methods of dealing with them are simpler and less sophisticated; for example, glue traps are inexpensive, easy to use and quite effective.
Rats are quite aggressive creatures. Sensing real danger, they are ready to attack even a person. In any case, these animals are not timid. Even if they are not going to attack, they are also in no hurry to run - freezing in place, they cautiously assess the situation and wait.
Their smaller brothers are not so brave; on the contrary, they are very timid. At the slightest rustle they run wherever their eyes look.
Childbirth
Mouse cubs are born in the dark. This usually occurs between midnight and 4 am. Before contractions begin, the animal's thirst increases, so it is important to ensure that the drinking bowl is always full.
The female climbs into the nest, which she has arranged in advance, and remains there constantly. Mice give birth in no more than 2 hours. The rodent does not need outside help. The mouse acts instinctively. She takes a comfortable position - lies on her side or sits on her sacrum.
When a baby mouse emerges from the birth canal, she pulls it out with her teeth, ruptures the amniotic sac and gnaws the umbilical cord. This is what the female does with all her cubs. Then she licks all the babies and eats the afterbirth. Baby mice are born every 5 minutes.
Attention! If there are mice in the litter that are too weak and have no chance to survive, the mother eats them. This is how she makes sure to feed healthy offspring.
What do the cubs look like?
At one time, a mouse can give birth to 5 to 9 pups. Newborn cubs are absolutely defenseless, since they are born without fur, they do not see or hear anything. The weight of the mouse is 1-1.5 g, and the body length is up to 2 cm. The thin skin of newborns has a red-pink color. The internal organs are visible through it.
When the mice are full, you can see the stomach, which looks like a white stripe on the stomach.
Young animals
The dimensions of a young rat pup are similar to those of an adult mouse. If we are talking about a black rat, then even a newborn animal is almost twice the size of an average vole. Other distinctive features are comparable to those of adult individuals.
One of the most common problems is distinguishing a small rat from an adult mouse. They are very similar and are often confused. Young rats have a pronounced blunt-nosed muzzle, while an ordinary mouse has a pointed muzzle.
The baby rat's tail is noticeably smaller, despite the large number of scaly rings (about 220). The vole's appendage is approximately equal to the length of its body, but with fewer rims (about 180). Rats have noticeable folds on their soles, while mice are smooth in this area. You can also distinguish two individuals by the size of their ears. In young rats they are shorter.
Growth and development of mice
In the first days of life, baby mice can only open their mouths, move their limbs and squeak. They navigate in space using their sense of smell. Thanks to him, babies can find a source of nutrition - the mother's nipple.
Around the fifth day, the mice's ears perk up and they begin to hear. A week after birth, the bodies of rodents become overgrown with fur. The eyes open on the 13-14th day of life. From this moment on, the mouse cubs actively explore the world around them - they leave the nest and try food from the feeder.
At three weeks of age, the pups already become independent and can be taken away from their mother.
Important! You should not touch newborn mice with your hands. During the initial inspection of the nest, it is recommended to wear gloves so that the foreign smell does not remain on the cubs, otherwise the female will eat the offspring or refuse to feed them.
At home, mice breed very quickly. But the female spends a lot of energy on bearing and feeding the cubs, and her health weakens. Therefore, it is important to control this process and not allow the mouse to become pregnant more than 5 times a year.
Caring for newborn rat pups
A rat cub is a defenseless, touching creature that requires increased care from its mother and owner. The mother will take care of the feeding and hygiene of the babies; the owner needs to properly care for the female and her offspring, without interfering with physiological processes. To do this, it is advisable to create comfortable conditions for newborn rat pups:
- In no case should you pick up or examine the cubs; the female may abandon or eat the brood from stress;
- the cage with the rat litter should be in the quietest, warmest and driest room;
- The rat cleans the nest on its own, throwing dirty pieces of bedding into the corner of the cage; the owner constantly needs to give the female clean napkins. You can remove used napkins from the cage no earlier than the 8th day of life, without touching the nest. If the rat becomes agitated when cleaning, put it down;
- watch the cage door, the cubs after the 8th day are very nimble and can jump out and crash on the floor, or the female will drag the newborns to any quiet corner of the apartment;
- feed the female with nutritious food and keep the drinking bowl filled with clean drinking water;
- Carefully introduce healthy complementary foods to babies for the proper development of the digestive system of newborns.
