A Sime begins to feel Need at, and after, half of the month's supply of selyn is gone. Need is the physiological imperative to replenish Selyn--i.e., to avoid death. It hits in direct proportion to the fear of death, and in inverse proportion to the Sime’s level of compassion for Gens, which is linked to the level of fear among the Gens surrounding the Sime. Gen fear sharpens the junct Sime's Need.
(From Mahogany Trinrose Ch 2, when Ercy Farris faced the prospect of dying before changeover was completed) 'Need was the periodic nightmare of every adult Sime, especially channels. What could it possibly be like to live with it? Some people said it was like starving to death. Some people said it was more like suffocating or drowning. If Halimer Grant stays, I'm going to find out what Need is like after all.' The reason Ercy thought "especially channels" was that in her time, (152 Unity) renSimes were prevented from feeling Need by timely transfers from channels, but to satisfy renSimes, channels had to experience Need firsthand and un-blunted, every month.
(Source: NOTES TO COPYEDITOR / To Kiss or To Kill (0 Unity)) “Need” is used only to refer to a Sime’s monthly Need for selyn, not to a need for money or food or love or anything else. If someone uses the word metaphorically to refer to something else, there is a reference to that fact in the text.
(Source: Index card file. House of Zeor) For channels, Need cycle not determined by available selyn reserves. "Symptoms" --- not thinking clearly, whole body is painful, ronaplin glands swollen, lumps stretching the skin, ronaplin oozing from lateral orifices. Metabolic rate increases, sensitivity up 50%, entire system "primed and yearning to function." Need is the predator sime's hunting mode. Personality changes: aggressive, inconsiderate. The desire of a Companion to help is comforting.
Need suppresses appetite, but sime can feel hungry if the body needs replacement material (as after a loss of blood.)
As Need grows toward loss of control, fast flickering eyes darting restlessly, measuring distances, very aware, laterals trembling, almost visible throbbing of the ronaplin gland, tension in voice. A "hyperactive predator intent on nothing outside of personal survival."
(Source: Index card file. SIME DICTIONARY) The sensation experienced by a sime when his selyn reserves are running low, generally once a month.
From the Unto Zeor, Forever Dictionary: The urgent demand a sime experiences when his selyn reserves are running low.
(Source: Index card file. Unto Zeor, Forever --- Third Draft) A Gen's hope "overpowering" to a sime in Need --- makes the sime ache. Emotions very close to the sensation of Need: Sweet yearnings and wrenching disappointments --- a mixture of feelings.
(Source: Index card file. Sime Surgeon http://www.simegen.com/sgfandom/rimonslibrary/surgeon/SURGEON1.html) To a sime in Need, relieving that Need would naturally seem more important than the lives of one or many Gens. A channel's feeling of Need always yielded to action, physical release, especially to movement toward a high field Gen.
ETIQUETTE --- Gross to argue unnecessarily with someone in Need (take up their time.)
THE "NEED EXPERIENCE" --- I must live! (But I can't) Urgent obsession at apex --- I'm afraid! I'm losing. I'm dying. Gen's reflexive response to Killmode attack makes sime desparate leest the Gen get away and leave him to die of attrition.
THE KILL --- No! I refuse to die! I will take what I need.
Marked by personality shifts --- quicker to lose temper, aggreessive. But Tecton, Escorted channels to control this reflex. Sime in need at the peak of his abilities. Hyperconsciousness --- sime perceptions dominant over sight, sound, smell, touch --- can "see" even furniture and a fly, in the energy fields --- positional and time sense (Psycho-spacial orientation) most keen.
PATHOLOGICAL CONDITION --- Digen's Need cycle "flattening out" --- pre-transfer days not as trying and Post not as relieving --- a deadly danger signal. When comes to transfer time, feels almost no Need. He and the Donor (Ilyana) must work to build it up (IS in Need but can't FEEL it.) Feeling Need a necessity of staying alive, or he might lose his desire for transfer in this condition.
(Source: Index card file. "Need" --- Attributed to Jacqueline Lichtenberg -- notes on article by J. Garrett) When selyn levels are low, body begins to cut back. Warmth goes first, then physical activity, signalling death by attrition when the sime can't hunt. Sex hormones (for sex drive) are among first cut back.
(Source: Index card file. The Channel's Exemption --- http://www.simegen.com/sgfandom/rimonslibrary/ce.html) System aching to function as Need grows --- even the channels "look into that cold abyss and know deep-driving terrors beyond Gen comprehension." Libido is "totally paralyzed" during this part of the cycle.