The external portion of the female chinchilla's reproductive tract is cone shaped, leading to confusion in determining sex. Tin the male chinchilla, there is no true scrotum. The testicles may be found in the inguinal canal area just below the skin between the back legs. The sex of young animals is best determined by the distance between the openings of the urinary tract and the rectum. In the female, and anus and urinary opening are close together, whereas the male has a wide separation between the openings.
Newborn chinchillas are quite precocious.
They are born fully furred, with their eyes open, and can soon walk. They can begin eating solid food within a week after birth but may not be fully weaned for 6 to 8 weeks. Although chinchillas can survive in a variety of environments, these animals thrive best in conditions that are similar to their Andean homeland. In turn heat stroke is a significant problem, especially in humid environments. Wire cages are traditionally used as housing for chinchillas.