General outline to get started (to be heavily edited as time goes on).

Mod is launched

Ecology of the Chaurus

• Chaurus are not natives of Nirn?
• How much of the chaurus existence that we see is shaped by the Falmer, and how much is natural to them?  Is there any natural behavior remaining, or is it all Falmer-centric now?
• The only place in vanilla Skyrim where chaurus can be encountered without Falmer nearby is in the swamps north of Morthal.  Are these escaped individuals, or is this near where they originally came to Nirn?  Most likely just best matches their preferred conditions: cold, standing water, cover and plenty of food.
• Considering the above and the conditions of the largest hive in Skyrim (Frostflow), it appears that chaurus prefer cold and wet areas.
• Population must be viable to have lasted so long, so how does their breeding cycle actually work?  Did an entire hive come to Nirn, or are they able to breed to large numbers with only a few specimens?
• Some parallels to xenomorphs
• Unclear if chaurus are meant to be warm-blooded. Their ability to operate without issue in dark, cold environments could indicate they are warm-blooded, or that their biochemistry is at least well-suited to cold.
• Probably nocturnal. Update: Non-flyers now have similar sunlight-related debuffs as vampires. 
• Should be immune or very highly resistant to their own form of acid.  They leak constantly from the mouths and seem not to suffer from it. Update: Improving poison resistance and immunity to other chaurus poisons.  Late-stage forms (Reaper tyrant for instance) gain an additional layer of poison effect that breaks through the immunity.  Instead making it so that lower chaurus forms cannot effect other chaurus with their poison.  This should cut down on hive-related friendly fire deaths when operating as a group.
• General "rules" of sex in TES Lore - when viable offspring is produced, it is always the same race as the mother
• Ovipositioning overcomes the TES breeding issue but adds some questions: why so many egg piles, but no hatchlings?  Are eggs constantly produced, but typically infertile?
• Falmer structures are made from masses of chitin. Are there massive Chaurus that produce so much, or can the chitin be shaped into larger structures?
• If there are behemoths, where are they found? What form do they take?
• Our only useful data on the innards of chaurus comes from the in-game book "Chaurus Pie: A Recipe" (https://en.uesp.net/wiki/Skyrim:Chaurus_Pie:_A_Recipe), which is useful for telling us that the poisonous bits of chaurus are in the head and legs, but not elsewhere.
• That is interesting given that the earwig-like forked tail is not poisonous, and may instead be a grasping mechanism or a display device.  If it is for grasping, maybe chaurus normally like to hang from things and ambush prey below.  (That would be a useful tactic combined with the acidic spit, but there are no in-game instances of this that I am aware of, and no way to rig it as a usable mechanism without extensive scripting and something that can handle complex ray-tracing to find suitable anchors.  That would be a modding nightmare and prone to breakage in a number of ways...)

Chaurus body types/castes

• Are Chaurus eusocial insects? (They actually aren't insects at all, but seem to share a lot of traits with them.)  If so, is there a queen?  Assuming for the time being that chaurus are eusocial, then there are several existing or inferred roles:
• Nymph or neonate "hatchlings" that are not grown yet.  These are seen in Estrus Chaurus, but I've never seen any actually grow to proper size, or even close to it.
• The "basic" chaurus would fill a generic behavior, unspecialized and likely acting as a soldier and/or drone.  There is a question of whether these are still considered to be adolescents in the overall hive structure, not filling a needed role yet.
• The Reaper would appear to be just a normal chaurus that has grown large.  Sources seem split on whether this is just a stage before turning into a hunter, or whether not all chaurus exit this stage at all, and simply stay in this state.  From in-game experience (heavily influenced by a large number of mods that may be interfering with normal distributions), Reapers appear to be both uncommon and more solitary.  I've never seen two Reapers sharing an area, so they may be prone to dominance displays.  It may be impractical or impossible for two Reapers to co-exist in the same area.  Large Falmer hives may have multiples, but given that the most prominent hive in the game (Frostflow) has only a single -- very large -- Reaper, I'm inclined to say that Reapers fulfill a queen-like role in the hive.  Update: it actually has a second reaper who is explicitly spawned in dead, reinforcing the idea that reapers don't coexist.
• Though Sexlab animations have not shown this to be the case, Reapers may be the equivalent to queens.  It is possible that as Reapers grow very large, they become the center of the hive.  In that case, they may be the fertilizing systems for all the egg piles we see, which would seem to be generated by the normal chaurus.
• If eusocial, are the chaurus locked into a particular form with only some of them transforming later in life, or does every member of a hive transition through different life stages?  It is unclear if all Reapers eventually chrysalis into Hunters.  Maybe only some of them do or the need to do so is environmentally driven.  It also appears that many Reapers perish in the process and fail to complete it.  Do these leftover husks have a role in the chaurus ecology?
• What role does the Hunter actually play in the life-cycle?  Is it purely predatory? A scout for hive growth/new hives?  Is it intended to bring food or breeders back to a central location?  Its role in a hive may be impossible to discern absent Falmer influence.  It is likely that they are either fertilizing agents, or genuine hunters, roaming far from the main hive to search for food/prey/breeders/other ill-defined opportunities.  Of course, in-game they always hang out near the spawning points and seem to not even patrol meaningfully.  We can infer this to mean their core purpose is disrupted by the Falmer, or that their role is purely as a soldier, and serve to defend the overall nest.  It is curious why they would need to fly for this role, as they are shedding substantial body mass (which in real terms means combat ability) to make this change.  It may be that the mobility is for rapid reaction, rather than any direct combat advantage, and if so seems to indicate that there should be a larger number of hunters so that they can mass strength.
• It would be very odd for another form to occur after the hunter that then sheds the flight abilities, but if transformation to hunter is driven by local chaurus population, then they may revert once they are far enough away from the origin.
• Life-cycle: Egg -> Nymph/Larva -> ?? -> chaurus -> (Reaper || Hunter) ? -> ?? -> Behemoths?
• It may be that there is a distinctive gender/genetic divider that dictates whether a given chaurus can become a Reaper or a Hunter.
• How do the Skyrim Immersive Creatures variants fit in? The hopper (ash hopper), crawler (spider), and warrior (draugr); These would have to imply that chaurus either naturally produce variant offspring (mechanism undetermined), or that they carry an infection that can spread to other species.
• Alternately, chaurus may not be singular organisms at all and instead arrange themselves into specific shapes as they grow, sometimes deviating from the norm to attempt to mimic other shapes in their immediate vicinity.
• All three of these forms could be indicative of another caste of chaurus altogether: the mimic.  The draugr-based version would probably be an attempt at mimicking falmer?  Maybe the hopper is just a juvenile mimic, or is trying to be like a skeever?

Potential life-cycle flow chart (left to right):

Potential carapace changes for Reaper Tyrants (just ideas right now)

• Mandibular crest (shown in picture above, will be glowing in the future). Partially done, absorbs health. Has the glowing effect, but I'm not satisfied with the way it looks in game.
• Flanges (also in picture above, extra spikes emanating from the sides). Done, adds armor rating.
• Knee spikes Done, increases unarmed damage.
• Bladed limbs
• Prominent dorsal spikes Done, adds armor rating.
• Extra ovipositors? (would be difficult to make this work reliably with all animations, but might be possible...)  Alternately, a pair (trio?) of normal chaurus-sized ovipositors might work better.
• Faux wings
• Translucent, prominent everted eggsac on back or belly
• Pheremonal coremata (tentacles, see creatonotos gangis https://www.google.com/search?tbm=isch&q=creatonotos+gangis&chips=q:creatonotos+gangis,g_1:coremata:FszSTYe4xsQ%3D&usg=AI4_-kQepDP6XSF7taIDxe56XHk4UygwHg&sa=X&ved=0ahUKEwjipY_VpariAhVKrJ4KHbhsBjIQ4lYIMigF&biw=1344&bih=758&dpr=1.25)
• Additional limbs
• Scorpion stinger

Function of eggs in the chaurus life cycle

• We assume that eggs produce chaurus, but have no direct evidence of this.
• Estrus Chaurus has the parasitic life cycle of 1) Impregnation to live host, 2) incubation time, 3) Birth/rebirth/final oviposition, 4) Delay prior to potential hatching, 5) Hatching.
• Is this just the "parasitic" life cycle, or is the parasitic function merely indicating this is how it is done with non-chaurus incubators?
• Maybe there is a missing chaurus species/life cycle role that is meant for proper breeding?
• If the chaurus breeding mechanism is inherently parasitic, does it harm the host?  Does it maybe enhance the host in some way to allow them to survive the process and be re-used?  It would seem more reasonable in a host-rich environment for the parasites to hatch inside and eat their way out, gaining sustenance as they go.  This is clearly not the method used in Estrus Chaurus, and it is rare to find carcasses or bones near eggs.  Chillwind Depths may be an exception, but the obvious ritual killing aspects of the final room make it clear that this is something the Falmer are doing, and is not necessarily related to the Chaurus themselves, besides feeding.
• The chaurus appear to prefer cold and wet environments.  Maybe warmth is needed for incubation?  If this is true, then a chaurus body form dedicated to incubation would have to be a very different type of creature.  This would lead to a more natural parasitic hypothesis.  Alternately, maybe they are able to use internal chemistry to create a "warm bath" within.
• Note that the eggs glow (especially with https://www.nexusmods.com/skyrim/mods/95612), as do non-hunter chaurus species.  Maybe there is a correlation between the glow and fertility?  Could also be an inverse correlation (with phosphorescence indicating infertility).  Seems more interesting visually and from gameplay for the degree of glow to be proportional to how "ripe" a chaurus is, with highly aroused specimens glowing the most.

Sexlab Chaurus traits (from animations) and other mods

• Vast majority of animations with heads moving have them moving left.  Like, 90+% of the time.  Only Evac has any that look to the right.  Probably animation oversight, but could reference a physical distinction.  Maybe they are asymmetrically oriented, and their musculature only allows for specific/unilateral movement arcs?  This might make sense if their natural evolution included massive and crowded hives where forced locomotive properties would be an evolutionary advantage.
• Many chaurus animations include kissing/some type of mandibular attachment to the head.  Is this instinctive? An expected capture condition for unwilling breeding hosts?  Is something additional being passed orally into the recipient?
• Baka has introduced the concept of the worm/larva in the Chaurus Hunter.  This is also present in parasite mod (Kyne's Gift), though the coloration is different.  Are these parasites that infect the chaurus, or a component of the chaurus themselves?
• The role of chaurus cum: Creates the grey goop in the egg piles.  Fertilizing agent? Paste for sticking the eggs to something? What function does it have in a live host?
• Role of the incubator: Why would chaurus stick eggs into someone?  Is it necessary for their life cycle? Instinct related to a non-present pair species from their home world?  Does this function to produce offspring?
• We see in Estrus Chaurus that "parasite chaurus eggs" are smaller than the normal chaurus eggs.   They can also hatch into very small "hatchlings" that will slowly grow in the presence of food and are potentially hostile to any non-chaurus, including the "birth mother".
• Are the egg piles found everywhere in Skyrim just masses of unfertilized eggs?  Their layout in some places appears intentional (see FrostFlow hive).  It is possible that the eggs are naturally produced at a fairly high rate, and that fertilized eggs are a rarity.
• The Falmer seem to have no use for the egg piles, save keeping them near breeding areas.  This may indicate that the falmer are sensitive to which chaurus are ready to produce eggs and when, and corral them at that time.
• How are eggs fertilized?  Is there a very small chance of any egg being fertile?  Are specific conditions required?
• All eggs in vanilla Skyrim are found underground, often in cold & wet areas.  There are exceptions though: Gloomreach cave doesn't appear cold.

Anatomical issues/explanations

• The long ovipositors used by the chaurus would likely be very painful to a man/mer host, hitting the cervix, and potentially passing deeper into the body, likely fatally so.  This is especially true for the Reaper.
• One solution to this would be that the ovipositor is more pliant and compresses within the body, not actually passing so deep.  It could form a docking arrangement with the womb or (in the case of oral/anal animations) similar internal chamber, with the "thrusting" actually being a frictional conveyance mechanism for the egg-laying.
• Another potential solution for this would be that the oral fixation and/or some type of precum causes changes in the host body to make them suitable and allow for massive apparent disruption of internal organs.  Reference as "bugcum".
• If this is the case, bugcum could also have a pacifying effect.  In the event that they are producing an additional chemical, that makes two distinct fluids being produced for external use: the poison spit and the pacifying saliva.  Combined with the possibility of significant metamorphosis (hunters) or major species differentiation (hopper/crawler/warrior), their ability to generate new materials from themselves is pretty remarkable.
• If the bugcum actually causes physical changes in the elasticity of the internal organs, how long does this persist?  Might it fade before birth? (probably killing the host).

Thoughts on additional forms/mods/integration

• Rogueshot's skeletons (https://www.nexusmods.com/skyrim/mods/95422 and https://www.nexusmods.com/skyrim/mods/94874) make significant changes to the shape that will likely throw off animations for Sexlab.  These skeletons could be used for non-fertile forms or stages of the life-cycle.  These would need to be different races with a new skeletal path and likely the "SexlabForbid" keyword.  Update: attempted to make a Baka ABC compatible variant of the RogueShot "Nightmare Chaurus" skeleton and the proportions are so ridiculously off in animations that I doubt it can work unless the base scale of the chaurus is very small. This *could* work if I decided to let later-stage nymphs lose the SexlabForbid keyword.  I would have to experiment with this a bit more.
• "Chaurus Lights" (https://www.nexusmods.com/skyrim/mods/44966) can be adjusted to detect arousal or animation-in-progress (presence of SexLabActive keyword).  UPDATE: Done with minimal fuss, now strobes the lights while fucking.  See below.
• Metabolically, the chaurus might have to consume a lot of food to grow while simultaneously producing so many infertile eggs.  Maybe the path to becoming a reaper involves not producing many eggs at all?  Maybe Reapers are inherently infertile most of the time?
• Maybe the chances of host survival depend on the type of chaurus using them as an incubator?  Reapers would seem to be the least survivable.

Elements needed in future mod

• Direct manipulation of the chaurus life-cycle events through feeding, sex and milking.  For instance: only having sex with a chaurus when it is at peak arousal will push it towards becoming a Reaper while regular milking keeps it at "normal" chaurus scale or pushes it to become a hunter?  Update: See above life-cycle image in spoiler for reference.  My thought at this stage is that Reapers will naturally fight one another, and the losers of these contests will molt into hunters (maybe dying in the process).  As a Reaper gains power and defeats more Reapers, it eventually molts into a Reaper Tyrant, which at present would be the most powerful form they could reach.  Base stats are about 30% higher than normal Reapers, and I was considering giving them a substantial boost to poison and some type of advanced breath weapon.
• Creation of a new chaurus form that is a Reaper with a multitude of (non-functional) wings, showing a reversion from Hunter to Reaper form at the establishment of the new hive.  Maybe other forms can be coerced into appearing.  Update: Currently calling this the "hybrid", and making it a possible evolution of the SIC mimic caste and Workers (standard chaurus) who temporarily bypass the dominance route.  My thought is that they may eventually challenge Reaper Tyrants, but are otherwise less prone to territorial displays than reapers.
• When a chaurus changes to a new form in the life cycle, it leaves behind an exoskeletal molt. (Probably just a translucent greenish ragdolled body.)  This would probably be a destructible object (hit it with a mace, flame, whatever to dispose), or maybe creates a new alchemy ingredient.
• I would like to find a way to make the odds of parasitic infection through EC+ be reliant on race (Reapers more likely, etc) and animation used (any animation with explicit egg laying), if combined with Chaurus Lights, it might be possible to visually detect a chaurus that is "ripe".  Likewise, oral impregnation should not be likely, or should have the effect of inhibiting the use of food.  This could be integrated into survival mods.  Update: Partially complete, see below.
• Needs to be an in-game mechanism for aborting the parasitic infection.  Update: Looking through the EC+ scripts, it looks like the estrus tentacles will do this.  For the record: I don't use the estrus components at all as I feel they don't mesh well with the chaurus form or themes.  To each their own, but my approach would be to have some type of alchemical concoction that does this (likely using some ingredients from the cast-off molts and maybe other things likely to be found in/around a hive.
• Egg-laying animations show full-sized eggs being implanted, but EC+ only uses very small ones.  Maybe animations that do not show egg-laying directly would produce the smaller ones (a slurry of bugcum and small eggs), while the more direct animations (BakaHuntingRape, Billyy Reaper Doggy 2, Anub's Egg, etc) would have larger eggs?  Maybe only Reapers implant full-sized eggs?  In this sense, hunters seem to be a step backward, due to scale.  Update: Bane Master has informed me that the birthing process can pop out virtually anything.  I haven't done it yet, but this seems straightforward enough with some tinkering of the base scripts.  Note that the base version of EC+ will only allow pregnancy/implantation with normal chaurus and reapers.  This can be bypassed by editing a formlist, and some modification to the scripts to juggle the chances with various forms.
• Should be a possibility of becoming addicted to the narcotic/pacifying effects of the saliva/bugcum.
• Maybe repeated use as an incubator or excessive exposure to the saliva/bugcum starts a "slimegirl" progression, as the elastic nature of the new form doesn't fully return to normal.
• Would like to see adjustments made to the progression of EC+ that make the body more resilient at earlier stages, but almost useless at later stages.  Maybe needs a certain level of health/stamina to survive the process.  This could include a lot of complications, such as not all the eggs being borne, or a premature hatching causing damage over time.
• While Untamed has the cleanest and easiest mechanism for controlling a hive, its method of hijacking all AI packages makes it unsuitable for use in many cases, and incompatible with anything that relies on behavioral AI to trigger.  Might need to replicate some of Untamed's features while removing most others.  The UI interface, naming, and general control functions are great though.
• Mechanism for initiating sex with chaurus, potentially multiple at once.  Update: Note that EC+ pregnancy is determined only by the first chaurus actor in the sequence, and only in the event it is vaginal.  This means that Billyy's 3p Spit-roast Anal animation should not produce infestation, but every other 3p+ animation should have a chance.  The issue here would come with seeing if one of the chaurus was particularly fertile, but that one didn't land in the "actor[1]" position of the array.  May want to have a keyword search for all actors in the array or just skip it and decide if the animation is Vaginal + gangbang, then the chances of infestation go to 100%.
• A set of traits that allow for further differentiation of individuals, maybe hinting at future nature.
• Common colorations found in different hives.  Add a Pokemon collection element to them.  
• Inherent ability to either appease/trade with Falmer or outright attempt to liberate the chaurus in the hive, maybe using varying levels of influence on the chaurus to turn them against their masters?  Maybe collecting eggs from a location can produce offspring of those colors/traits?  For this to work, there would need to be a self-insemination option using the eggs.

Current Plans and Progress:

• Apropos synonym edit for many egg-laying and chaurus-related terms: Ongoing and never fully "finished".  Currently stands at 1800 lines in synonyms.txt and triggers reliably if kept around this number.  (This was once over 3000 lines and would fail miserably most of the time, being just too much for json to contend with.)
• Apropos rewrites for custom animations: Ongoing, around 30% finished.  These are formatted for use at 15pt font and 400 (max) width.  Even so, they run over the edge from time to time.  Working on getting the descriptions smaller when this happens.
• Non-hunters now suffer health and stamina debuffs in sunlight, same as vampires (duplicated the effects to avoid compatibility issues with vampire mods).
• The poison of lesser chaurus (nymphs, workers), no longer effects other chaurus.  Reaper and hunter poisons do still harm other chaurus.
• New animations: Note that "new" = combination of existing animation assets into a new format.  Currently have three finished, three more in process and four that are tweaked versions of otherwise unchanged animations (main changes are sound/tag adjustments, intro sequences and cumshots).  Due to the multiple assets being used from different animators, I am unsure of how permissions would work on these and if they can be shared.
• Cumshot: converted two variants of the particle meshes from Cumshot 2.1 for use on chaurus, one for big spray and another for a sprinkling of precum.  At present, these need to be added manually to the animations as AnimObjects, but there isn't anything preventing their potential use as ArtObjects to be attached dynamically through scripting.
• Currently using five additional colors, based on various retextures found on Nexus, including (https://www.nexusmods.com/skyrim/mods/6962, https://www.nexusmods.com/skyrim/mods/6737, https://www.nexusmods.com/skyrim/mods/18476).  I did these a long time ago and somehow have five total recolors.  I might've tweaked or created the other two, but I don't remember now.  These colors are presently used randomly, but I will make them location-based.  All colorations are present for all six main chaurus body types (nymph, worker, reaper, tyrant, hunter fledgling and hunter).
• Finished: Jsons for MNC/Creature Framework to pick up the correct armor and arousal, not losing the colorations in the process.
• Want to add a layered coloration system similar to The Dragon Engine to give more visual distinction. Something subtle, but noticeable that allows for visual differentiation in a large hive.
• Another option for this is "armors" that may show slightly different placement of spikes or minor adjustments. Update: The procession from reaper to tyrant is marked by the addition of armored body features.  Working up a script that "awards" a killer a bit of armor if they have the keyword "ChaurusDominance".  This is an Event OnDying script and basically only gives reapers and tyrants a gift.  As it stands, if a Reaper is awarded one of these, the idea is they will trigger a quick molt stage into tyrant (widening, scale to 1.1, equips whatever armors they have).  As time goes on, they collect more and more armors, helping to give them a unique appearance.
• Chaurus Lights script adjustment for strobing during sex (done, see "chliglowcontrollermescript" below).  Note that this will not automatically update lights on existing chaurus already near you.  It will only work on newly added lights.  You can (potentially) remove the spell effect and restart it in console to make it update.  Still to do: make this sensitive to stage and orgasm, building the strobe effect faster as it reaches climax and spiking at orgasm.
• Estrus Chaurus Script adjustment to be cognizant of racial subtype and to have a percentage based change of infection instead of guaranteed. Partially done (see "zzestruschaurusae" below).  Gives a 25% chance to be impregnated if it is a normal Chaurus (worker), 50% for Reaper, and guaranteed if the animation is vaginal and has the tags "Eggs", "Oviposition", or "Breeding".  Right now, only Babo's Reaper anim and Billyy's newer ABC-based animations have some/all of these tags, so manually adding them may be needed.

chliglowcontrollermescript.psc chliglowcontrollermescript.pex

zzestruschaurusae.psc zzestruschaurusae.pex