lets see:
if feegles were implamented they would be an skulking type creature.
can_talk can_learn -fast lerners as well-, building destroyer 1, can open doors, would be appropiet. as for the theift tag, is their any way to chance the kidnapping tag to kidnapp animals/none sentients? if not then should probably leave theft out and just have it as move your stuff about, woul certiainly make vaults more vauble for your artifacts, and eat your food/booze.
giving them small knifes as their weapons, maby a unique bag called a spog for 1 item, good dodge ability as standard because theyll never use sheilds, 1 kelda: 1 bigman: 1 gonnagle: 20 or 40 feegle clanmen. maby 1 duaghter as a random who when grows up leaves the map if kelda is still alive and has a 80% chance to take over a neighbour clan and a 20% chance to start a new one, with a new kelda arriving if the one on the map dies within a few years or so, -or if can be linked ot outside world the better-. -unless turned into a civ who could at some point be played then these ratios are just guidelines, since a clan can be from 40 to 150 individuals in one feegle mound-
random civ politics like: can read or dont wash would be good descriptors for likes/dislikes in dorfs.
have thier corpses leave no miasma as well, since their small and thiers so many of them and they dont wash normaly the smell would be neglagable.
i would suggest that your expedition leader can have an option to open diplo talks with the kelda if their on the map. -since a kelda dosent leave the mound unless said mound is attacked- or the clan gonnagle/ have the clan gonnagle or bigman act as the feegle diplo and have an option for a clan to move in with you? depending if you have a memorial hall or a tomb of a sufficent level/size for them to move into -since feegles live in burial mounds as usual-. hell, you could have is so that you can offer x amount of booze or the feegles join your dorfs partys to try and make freinds with them. and if you dont do anything they are neutral and will nick your food/booze. if attacked get ambushes untill you have talks wiht their diplo again for a settlement deal. probably of booze. players could easly plan for feegles by stepping up their booze production to about 1/3 more than they need and making some kind of mound outside of the fortress for them to inhabit/pour forth forth in an angry tide to attack seigers who get too close to the mound.
as for their life style: ide say, born, 6 months as baby, then 3 years as child, then can live up to about 30 or so. -since they reproduce fast, this will make sure they dont overrun every other civ- ide also say born in groups between 4 and 12. with a pregnancy period of about a year.
theyde be no eat sentients as well. so: Nac mac feegle vs elves war anyone? ^^