A fertilized egg in ARK: Survival Ascended won’t hatch unless you hold it at the right temperature — get it wrong and the egg steadily loses health and dies. Incubation is the gateway to breeding, so getting it right matters. This guide covers fertilized vs unfertilized eggs, the temperature system, every way to control temperature, and how to keep a baby alive the moment it hatches.
Fertilized vs unfertilized eggs
Creatures drop unfertilized eggs regularly — these are food and kibble ingredients; they never hatch. A fertilized egg only appears after a male and female of the same species mate. Only fertilized eggs incubate into babies, and only fertilized eggs need temperature control.
Why temperature matters
Each species’ fertilized egg has a specific temperature range. Drop the egg and read its status — it tells you whether it’s too hot or too cold. While the temperature is wrong, the egg’s health drops; if it hits zero, the egg is lost. Your only job during incubation is to bring the surrounding temperature into the correct band and hold it there until the egg hatches.
Ways to control temperature
- Air Conditioners — the cleanest, most reliable method. A ring of ACs around the egg holds a stable temperature for almost any species; add or remove ACs to fine-tune. This is what most breeders use for a permanent hatchery.
- Standing Torches / Campfires — cheap heat for cold-climate eggs; place more or fewer to dial in the temperature.
- Incubator — the late-game device that lets you set an exact temperature and even improves mutation odds; ideal for serious breeding operations.
- Location & weather — the ambient climate does half the work. Hatch desert eggs in a hot biome and snow eggs in the cold, then top up with ACs or torches.
- Dimetrodon — this creature radiates insulation; sitting an egg near tamed Dimetrodons can hold temperature naturally.
Building a hatchery
A dedicated hatchery room with a ring of air conditioners (powered by a generator) is the breeder’s standard setup. Build it once, tune the AC count, and you can incubate most species in the same room — just adjust for the occasional extreme-temperature egg.
Incubation time & hatching
Once the temperature is right, the egg incubates over a set time, then hatches into a baby that immediately needs food in its inventory — so be ready with meat or berries before it pops. From there you’re into the raising and imprinting phase covered in our breeding & imprinting guide.
Get exact temperatures & times
Every species needs a different temperature and incubation time. Our free ARK Egg Incubation tool gives the exact temperature range and hatch time for each creature, so nothing dies in the shell.
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