Springtime down on the farm is a great time for kids to learn about nature, where the leftovers from producing their dinners goes to and where their fur coats come from.

March is mating season for mink, and fur farming families are busy from sunup 'til sundown. The mink has "induced ovulation", which means a mating is needed before the female's eggs are released. The fertilized eggs, blastocysts, descend to the oviduct but can remain dormant for some time before implanting. Due to this delayed implantation, the pregnancy period may range from 38 to 100 days, but with an average of 45 days from the last mating.

In April, the kits arrive. In 2001, the first litters were born on US fur farms as early as the second week of April, just before Easter. Farmers were reporting that whelping was going well and they are now hoping for good weather conditions over the next couple of months to ensure the survival and growth of the kits. This year's crop of mink is expected to number about 2.8 million animals! That's a lot of hungry mouths to feed!

The litter size varies, but can number as many as 15. In farm conditions, the production average (kits per mated female at weaning) is 4 or 5. At birth, the kits are naked and blind, and weigh about a third of an ounce (less than 10 gm). They grow rapidly and at weaning, when 6 weeks old, weigh about 11 ounces (300 gm). A full-grown female mink will weigh about 2 pounds 4 ounces (1 kg), while a male will be twice or even three times her size.

The reproduction cycle of farmed foxes is tied to the season. "Heat", the period when a female is receptive and can be impregnated, normally occurs only once a year. The breeding season is usually in February and March, and heat lasts from 1 to 5 days. Gestation lasts 52 days and litter size can range from 1 to 12 pups, but is usually from 4 to 6. At birth the pups weigh about 3 pounds 4 ounces (90 gm), have a faint fur coat, and are blind, not gaining their sight for 17 or 18 days. The pups will normally suckle milk until 3 weeks old, then begin eating the same feed as the mother. They are usually weaned when 7 weeks old, weighing about 3 pounds 5 ounces (1.5 kg). The fox is fully grown at 28 to 32 weeks. Selective breeding has increased the size of farmed foxes remarkably, with adult males weighing 13 pounds to 15 pounds 8 ounces (6 to 7 kg) and females 10 to 13 pounds (4.5 to 6 kg).