I have been keeping rats for dome years as I keep snakes but find it strange that this year for the first time I`m getting rat births.Rats go in and out of heat every 3-5 days year long. They can get pregnant and give birth at any time of the year. And yes, other females do help to raise litters.
My rats only breed during the warmer months so I find it strange that this year the little critters cant wait.Yes, but rats do not ovulate on a yearly basis, they ovulate year round every 3-5 days. I would find it more strange to have male and female rats together and not have babies.
The time of year is irrelevent to the estrous cycle of a rat.