Gachas throw temper-tantrums when not mate boosted. So remember if you want to farm them keep them far apart from same sex gachas and each should have their own mate. Ex. 2 f and 1 m can make them get jealous with purple lights and vise versa.(they will refuse to take anything and won't produce anything.
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