UOA-IVs, more commonly known as "Caretakers", are large robotic arthropods, armed with a variety of heavy weapons, though almost always including one ventral heavy machine-railgun. Caretakers only roam the interior of Black Factories; their function is to patrol, protect, maintain and expand said facility. Because of this, their "hands", which vary in number, are actually fairly dextrous. UOA-IVs are more curious than they are aggressive, but lacking humanity, they will not hesitate to live autopsy a disarmed human raider on a rock, and without anaesthesia. When a Black Factory reaches a certain productive limit, a number of caretakers will stockpile resources and tunnel to a far off location, where another one will be established. This behaviour is similar to how ants create new colonies.