Females typically raise litters only in alternate years, although both greater and lesser frequencies have been reported on occasion.
They are mostly solitary animals, and the mother raises litters of up to four young on her own.
The breed's maternal skills enable it to raise large litters of piglets on pasture.
Egg-rustling, night-howling varmints are raising litters in storm drains, golf courses, parks and cemeteries.
The burrow, the entrance to which the mouse covers during daylight hours, is also used to raise litters of between 2 and 7 young.
Females are polyestrous and can raise several litters a year; in captivity, breeding takes place year-round.
It protects the animals against predators and temperature extremes and is an ideal place for raising litters.
There were 16-20 rats of both sexes in residence, an abundance of food, balls and wheels for play, and enough space for mating and raising litters.
Skunks are nomadic, and will move on unless they are raising litters.
"They produce young and heavily and they raise big litters despite a lot of human interference, which is quite amazing, actually."