Thank for the help, mate.
Here's are the raws for the purring maggots in case anyone's interested (It goes in creature_subterranean.txt):
################################################################
[CREATURE:MAGGOT_PURRING]
[DESCRIPTION:A tiny larva which is prized for its milk.]
[NAME:purring maggot:purring maggots:purring maggot]
[CASTE_NAME:purring maggot:purring maggots:purring maggot]
[CHILD:1][GENERAL_CHILD_NAME:purring larva:purring larvae]
[LITTERSIZE:2:5]
[CREATURE_TILE:'{'][COLOR:7:0:1][ALTTILE:'}']
[PETVALUE:10]
[PET]
[BENIGN]
[NATURAL]
[COMMON_DOMESTIC]
[LARGE_ROAMING]
[BIOME:SUBTERRANEAN_CHASM]
[UNDERGROUND_DEPTH:1:2]
[POPULATION_NUMBER:250:500]
[PREFSTRING:comforting whirs]
[NOBONES]
[BODY:BODY_WITH_HEAD_FLAG:HEART:GUTS:BRAIN:MOUTH]
[BODY_DETAIL_PLAN:STANDARD_MATERIALS]
[REMOVE_MATERIAL:HAIR]
[REMOVE_MATERIAL:BONE]
[BODY_DETAIL_PLAN:STANDARD_TISSUES]
[REMOVE_TISSUE:HAIR]
[REMOVE_TISSUE:BONE]
[BODY_DETAIL_PLAN:EXOSKELETON_TISSUE_LAYERS:SKIN:FAT:MUSCLE]
[HAS_NERVES]
[MAXAGE:3:4]
[APPLY_CREATURE_VARIATION:STANDARD_WALK_CRAWL_GAITS:9000:8900:8825:8775:9500:9900] 1 kph
[APPLY_CREATURE_VARIATION:STANDARD_CRAWLING_GAITS:9000:8900:8825:8775:9500:9900] 1 kph
[USE_MATERIAL_TEMPLATE:GOO:GOO_TEMPLATE]
[BLOOD:LOCAL_CREATURE_MAT:GOO:LIQUID]
[BODY_SIZE:0:0:1000]
[BODY_APPEARANCE_MODIFIER:LENGTH:90:95:98:100:102:105:110]
[ALL_ACTIVE]
[CANNOT_JUMP]
[NO_DRINK][NO_EAT][NO_SLEEP]
[HOMEOTHERM:10067]
[CASTE:FEMALE]
[CASTE_NAME:purring maggot:purring maggots:purring maggot]
[FEMALE]
[USE_MATERIAL_TEMPLATE:MILK:MILK_TEMPLATE]
[STATE_NAME:ALL_SOLID:frozen dwarven milk]
[STATE_ADJ:ALL_SOLID:frozen dwarven milk]
[STATE_NAME:LIQUID:dwarven milk]
[STATE_ADJ:LIQUID:dwarven milk]
[STATE_NAME:GAS:boiling dwarven milk]
[STATE_ADJ:GAS:boiling dwarven milk]
[PREFIX:NONE]
[MULTIPLY_VALUE:2]
[MILKABLE:LOCAL_CREATURE_MAT:MILK:7500]
[USE_MATERIAL_TEMPLATE:CHEESE:CREATURE_CHEESE_TEMPLATE]
[STATE_NAME:SOLID:dwarven cheese]
[STATE_ADJ:SOLID:dwarven cheese]
[STATE_NAME:SOLID_POWDER:dwarven cheese powder]
[STATE_ADJ:SOLID_POWDER:dwarven cheese powder]
[STATE_NAME:LIQUID:melted dwarven cheese]
[STATE_ADJ:LIQUID:melted dwarven cheese]
[STATE_NAME:GAS:boiling dwarven cheese]
[STATE_ADJ:GAS:boiling dwarven cheese]
[PREFIX:NONE]
[CASTE:MALE]
[CASTE_NAME:purring maggot:purring maggots:purring maggot]
[MALE]
[USE_MATERIAL_TEMPLATE:MILK:MILK_TEMPLATE]
[STATE_NAME:ALL_SOLID:frozen dwarven milk]
[STATE_ADJ:ALL_SOLID:frozen dwarven milk]
[STATE_NAME:LIQUID:dwarven milk]
[STATE_ADJ:LIQUID:dwarven milk]
[STATE_NAME:GAS:boiling dwarven milk]
[STATE_ADJ:GAS:boiling dwarven milk]
[PREFIX:NONE]
[MULTIPLY_VALUE:2]
[MILKABLE:LOCAL_CREATURE_MAT:MILK:7500]
[USE_MATERIAL_TEMPLATE:CHEESE:CREATURE_CHEESE_TEMPLATE]
[STATE_NAME:SOLID:dwarven cheese]
[STATE_ADJ:SOLID:dwarven cheese]
[STATE_NAME:SOLID_POWDER:dwarven cheese powder]
[STATE_ADJ:SOLID_POWDER:dwarven cheese powder]
[STATE_NAME:LIQUID:melted dwarven cheese]
[STATE_ADJ:LIQUID:melted dwarven cheese]
[STATE_NAME:GAS:boiling dwarven cheese]
[STATE_ADJ:GAS:boiling dwarven cheese]
[PREFIX:NONE]
[SELECT_CASTE:ALL]
[SET_TL_GROUP:BY_CATEGORY:ALL:SKIN]
[TL_COLOR_MODIFIER:GRAY:1]
[TLCM_NOUN:skin:SINGULAR]
[SELECT_MATERIAL:ALL]
[MULTIPLY_VALUE:2]
################################################################
They reach adulthood in 1 year, live between 3 and 4 years, between 2 and 5 can be born at once and both males and females can be milked roughly every 6 or so days, when butchered they only yield a little meat, fat and skin because they're pretty small, so they're mainly for the milk industry.
I've never really used the milk and cheese-making industry, it's just a bother to micro manage everything, and i always ended up forgetting that i had milkable animals, i hope to change that with this.
I also wanted to make some shearable pre-existing underground animals, but none of them sort of fit in, i thought about rutherers and dralthas, but they're too big and take too long to reach adulthood, plus dralthas are like underground elephants and eat pastures too damn fast.