The creature chamber consists on two nods that proyect a kind of energy beam that flashes for a second to then, deliver the new created creature.
As the key structure that supplies the army with creatures, if destroyed and no creature are there to defend the lab, it will be very difficult to pull back enemies to build another one.
The nods create a type of electromagnetic field for a period of time. This time usually depends of how much resources the creature will consume.
The first creature chamber was built shortly after the Tunguska Event. It allowed to combine two animals into a new different creature.