Shipping fertile eggs by post dates back to the early 1900s hatchery catalogs, when rail and parcel post let small farms buy bloodlines they could never drive to.
Today the same trade runs on breeder-to-breeder sales: a box of a dozen eggs moves genetics across the country for a fraction of the cost of shipping live birds.
Care & housing
Unpack immediately and rest eggs pointy-end down at room temperature for 12-24 hours so the air cells can resettle.
Set at 99.5°F forced-air, 45-55% humidity, turning at least three times a day until lockdown on day 18 (chicken) or by species.
Candle on day 7 and day 14 and pull clears and blood rings to keep the incubator clean.
Breeding tips
Expect 50% hatch on shipped eggs as a good result — scrambled air cells, not fertility, cause most losses.
Collect breeder eggs twice daily, store no more than 7-10 days at 55-60°F, and never wash eggs you intend to hatch.
Run one rooster per 8-12 hens for reliable fertility; too many males lowers it.