The Gacha cannot be carried by any Extinction flyer. They also require being spread out about 12 foundations apart IF they’re the same gender. Breeding pairs are okay. You must manually turn their resource collection ON after taming; it is off by default. They eat meat as babies and all levels should be placed in Crafting Skill. Also, take a look at their production tab! Each gacha has a custom loot pool and you can choose specific resources for it to drop, which will NOT impact your chances of getting items.
Gachas are essentially living lootboxes and resource farms. They will eat anything (including stone, wood, or fiber) and turb it into crystals which can drop a variety of resources including black Pearl's, organic polymer, or obsidian, among other things. They also have a rare chance to drop higher-tier crystals which turn into upgraded armor and tools