How long do rats live
Scale of equivalent aging schedule for rats compared to humans:
How long do rats live ? Rat Age to Human Age
5 weeks ………………………….. 10 years
6 months ………………………….. 16 years
9 months ………………………….. 25 years
1 year …………………………… 35 years
1 1/2 years ……………………….. 50 years
2 years ………………………….. 65 years
3 years ………………………….. 85 years
4 years ………………………….. 100 years
5 years ………………………….. 110 years
6 years ………………………….. 120 years
7 years ………………………….. 130 years
How long do rats live In the wild ? Rats live an average of two to three years, while captive rats generally live three to five years.
Life cycle of rats: How is their ability to reproduce ?
The gestation of the female lasts 22-24 days with 8-12 nests per year. Each nest has 8 to 12 individuals with a survival rate of 12 to 20 individuals per female per year.
Female reproductive characteristics:
The females of this species are continuous polyestrous anatomically have similarities with the mouse reproductive tract, the infundibulum is surrounded by a pocket formed by the mesosalpinx, this is called the ovarian sack.
With respect to the uterus, uterus bicornis have the peculiarity to have two cervices, one for each horn, connected by a single vagina.
The mammary glands are 12 distributed 6 in the thorax and abdomen 6, are 6 pairs of nipples.
Females are born with closed vaginal canal, this newly-opened after 72 days of life with a range of 34-109 days, this variation is influenced by nutritional, genetic and environmental factors.
The first estrus is given to 40-75 days but only covers 90 days since crossing early produces more spaced births, dystocia at birth, infants with weight and size, these conditions also occur when the crossing is late, the most fertile age is 100-300 days and the last heat is given at 12-18 months.
The vaginal opening, ovulation and subsequent estrous cycle are correlated .A change in light intensity, a stressful situation can act on the pineal gland and the adrenal can alter the established order delaying or accelerating one of the events.
Male reproductive characteristics:
One of the salient differences between mice and rats is that rats can live among males without these squabbling, which in mice is impossible.
Testicular descent occurs 15-50 days, male sexual maturity occurs at 40-60 days with a weight fluctuating between 100-140 grams, it is important to note that the male sexual maturity also implies an improvement in quality and sperm viability.
The pre copulatory behavior is characteristic, no biting of the head and body of the female by the male, or to conduct a review of the genital and anal regions of the female ejaculation time is 10-20 seconds, sperm They are elongated and head hooked.
Pregnancy and childbirth:
Gestation lasts 22- 24 days, the placenta is discoid and hemocorial.
The ovaries are essential for maintaining pregnancy, whether to proceed to an ovariectomy at any stage of pregnancy, inevitably an abortion will occur or, failing resorption of fetuses will occur because the placenta does not produce enough progesterone to maintain gestation.
An average of 9 pups are born (8-12) by birth, the mother’s age and physical conditions determine the time of delivery. Dystocia occurs in females with low serum levels of vitamin A.It is also related to the number of pups born.
How long do rats live in reality can really not be easily determined,because their life is full of constant fear of death. Rat poison,cats,other rats etc. are just some of the very dangers that rats face every day.
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