Ferrets (Mustela furo) are common but unconventional pets. They are from the mustelid family, which includes weasels, badgers and polecats. Unaltered male ferrets are called hobs, and unaltered females are called jills. Ferrets are photoperiodic in their breeding cycle, which means that longer daylight hours will trigger aggression and territorial behavior in the hob and will trigger estrus, or heat, in jills.
The Mating Process
Ferrets reach sexual maturity between 5 months of age and 9 months of age, and they remain fertile for three to four years. Because of their photoperiodic breeding tendencies, female ferrets who are exposed to natural light will go through cycle after cycle during the spring and summer months. When a jill in estrus is paired with a hob who is ready to mate, the result will be an aggressive and seemingly violent process. The ferrets will mate several times over a few hours or an entire day.
The gestation period for a pregnant ferret is typically about six weeks -- 38 to 44 days. About a week before the jill is ready to give birth, she should be separated from other ferrets in her enclosure. She will begin nesting with whatever materials are available. Some jills begin to pull out their own fur to build a nest to prepare for the whelping process. At this point, give your pregnant jill an ample amount of food and water, as you do not want to disturb her once the birthing process begins.
When the jill goes into labor, it is imperative that she is left alone to give birth. A jill who is bothered during the birthing and nursing stages may kill and eat their young, especially her first litter. She will need her privacy to have her kits, and should be interacted with only if something appears to be going wrong. Signs of difficulty during pregnancy are glossy eyes and weakness. In these cases, seek veterinary attention immediately.
Jill in Labor
The exact length of the labor period for a jill will vary. The delivery process for the entire litter can take as few as two or three hours, but longer is not abnormal for larger litters or older jills. However, if your jill appears to be in labor for longer than 24 hours, seek veterinary attention quickly -- she could be suffering from complications, such as a kit being stuck inside her.
Newborn Kit Development
The average ferret litter has about eight kits, who are born without fur and with closed eyes and ears. Their fur will begin to grow in after about a day. They will nurse continuously. Their ears and eyes open, and their coats fill out by the age of 5 weeks. At 8 to 10 weeks, they will be eating solid food and drinking water on their own.