Cave spider - Giant cave spider
- A tiny underground bug, sought after for its thread.
A cave spider is a type of vermin. It produces webs that can be collected and woven into cave spider silk thread. Cave spiders can be annoying and beneficial at the same time. They will usually hang out around underground areas like caverns or underground water sources. They will leave webs around these areas or even in your fortress that can be collected via the 'collect webs' job at the Loom, which is created automatically when webs are around. They can be annoying because they will bite the occasional pet or dwarf, though they're only mildly venomous. Cave spiders are hateable vermin and will produce an unhappy thought for dwarves who detest them.
 Pest Control
If you have cats around your fortress, they will hunt cave spiders down without mercy just like any other vermin, and this can be a bit annoying if you want those webs. You can attempt to solve this problem by confining all unattached cats using cages or restraints and eliminating cats that have adopted a dwarf, but this approach can cause happiness issues, and migrants will continue to introduce pet cats to your fortress.
Assigning pet cats to a small, out-of-the-way room designated as a pasture can effectively restrain them without causing the dwarf happiness issues killing them would. Be aware that assigning many cats to too small a pasture will result in catfights.
 Use in Industry
Unfortunately, taming a cave spider does not provide a source of controlled silk production, as cave spiders in cages will not spin webs. Because of this, a silk farm requires an area (potentially cleared and sealed, for dwarven safety) in which the vermin can run wild. Since cave spiders do not reproduce like creatures, any such farm will need to be in a biome that generates cave spiders. You can also dig out a room in an upper level (near your loom) and attach a lever to a placed cage - - (much the same as you would with caged goblins, though be sure to tame the spiders), once the cage has been filled with tame cave spiders, - - pull the lever, releasing the spiders (that have been caught in an animal trap baited with meat), they will be released and begin filling the area with webs without your dwarves and pets having to deal with bites.
[CREATURE:SPIDER_CAVE] [DESCRIPTION:A tiny underground bug, sought after for its thread.] [NAME:cave spider:cave spiders:cave spider] [CASTE_NAME:cave spider:cave spiders:cave spider] [CREATURE_TILE:249][COLOR:7:0:0] [CARNIVORE] [PET_EXOTIC] [PARALYZEIMMUNE] [WEBIMMUNE] [NATURAL] [BIOME:SUBTERRANEAN_WATER] [BIOME:SUBTERRANEAN_CHASM] [UNDERGROUND_DEPTH:1:2] [VERMIN_GROUNDER][VERMIN_HATEABLE] [POPULATION_NUMBER:250:500] [SMALL_REMAINS] [SPEED:2900] [PREFSTRING:mystery] [ALL_ACTIVE] [NO_SLEEP] [HOMEOTHERM:10040] [SWIMS_INNATE][SWIM_SPEED:2500] [NOT_BUTCHERABLE] [NOPAIN][EXTRAVISION][NOSTUN][NOFEAR] [NOBONES] [BODY:SPIDER:2EYES:HEART:GUTS:BRAIN:MOUTH] [BODY_DETAIL_PLAN:CHITIN_MATERIALS] [BODY_DETAIL_PLAN:CHITIN_TISSUES] [USE_MATERIAL_TEMPLATE:VENOM:CREATURE_EXTRACT_TEMPLATE] [STATE_NAME:ALL_SOLID:frozen cave spider venom] [STATE_ADJ:ALL_SOLID:frozen cave spider venom] [STATE_NAME:LIQUID:cave spider venom] [STATE_ADJ:LIQUID:cave spider venom] [STATE_NAME:GAS:boiling cave spider venom] [STATE_ADJ:GAS:boiling cave spider venom] [PREFIX:NONE] [ENTERS_BLOOD] [SYNDROME] [SYN_NAME:cave spider bite] [SYN_AFFECTED_CLASS:GENERAL_POISON] [SYN_IMMUNE_CREATURE:SPIDER_CAVE:ALL] [SYN_INJECTED] [CE_DIZZINESS:SEV:10:PROB:100:RESISTABLE:START:5:PEAK:100] never ends! [USE_MATERIAL_TEMPLATE:SILK:SILK_TEMPLATE] [EXTRACT:LOCAL_CREATURE_MAT:VENOM] [VERMIN_BITE:10:bitten:LOCAL_CREATURE_MAT:VENOM:LIQUID] [WEBBER:LOCAL_CREATURE_MAT:SILK] [BODY_DETAIL_PLAN:EXOSKELETON_TISSUE_LAYERS:CHITIN:FAT:MUSCLE] [BODY_DETAIL_PLAN:STANDARD_HEAD_POSITIONS] [USE_MATERIAL_TEMPLATE:SINEW:SINEW_TEMPLATE] [TENDONS:LOCAL_CREATURE_MAT:SINEW:200] [LIGAMENTS:LOCAL_CREATURE_MAT:SINEW:200] [HAS_NERVES] [USE_MATERIAL_TEMPLATE:ICHOR:ICHOR_TEMPLATE] [BLOOD:LOCAL_CREATURE_MAT:ICHOR:LIQUID] [CREATURE_CLASS:GENERAL_POISON] [GETS_WOUND_INFECTIONS] [GETS_INFECTIONS_FROM_ROT] [USE_MATERIAL_TEMPLATE:PUS:PUS_TEMPLATE] [PUS:LOCAL_CREATURE_MAT:PUS:LIQUID] [BODY_SIZE:0:0:50] [MAXAGE:1:1] [HOMEOTHERM:10040] [CASTE:FEMALE] [FEMALE] [CASTE:MALE] [MALE] [SELECT_CASTE:ALL] [SET_TL_GROUP:BY_CATEGORY:ALL:CHITIN] [TL_COLOR_MODIFIER:WHITE:1] [TLCM_NOUN:chitin:SINGULAR] [SET_TL_GROUP:BY_CATEGORY:EYE:EYE] [TL_COLOR_MODIFIER:BLACK:1] [TLCM_NOUN:eyes:PLURAL]