Creatures from earth evolved for four reasons called the "Four f's", fighting, fleeing, feeding, and fuc- fornicating. -- Anon Guest
Four fine instincts to make life continue are very important on Deathworlds like Terra. Fight or Flight are just two of them. The third -Feed- keeps the living alive and the dependent upon them alive as well. The fourth... let's call it Fornicate... continues the evolving population through preference-based selection. Deathworlds have many opportunities for fatalities, therefore the compulsion to breed is at a matching high.
Well. That is what's assumed to be the norm. There's anomalies for every situation, and every normally instinctual circumstance. Starting with the most controversial...
Fornicate: Allie took more precautions than normal. Well, what passed for normal on this world. She wanted to be unapproachable, but not overtly so. Those who did the unwelcome approaching were wont to attack those they found ugly, so she balanced on the razor's edge between pretty enough to blend in and ugly enough to ignore. Her clothing was plain and staid. Another razor's edge, this time between long enough to avoid attacks and short enough to do the same. There were authorised defense objects at her ready reach and, because this was one of those worlds, a chastity belt.