Hornbills, female sealed in tree hole nest. Male seals female s cloaca with a kidney secretion. Male propulsively fires his genitalia into the female s genital opening. She can t remove them. Living mating plug.
Pairs remain in copula for three weeks.
Chemical signals to other males that a male has already successfully mated with a female or may chemically cause the female to become non-receptive. Helioconius erato . Males produce a repellent in the late pupa stage to turn off males and stop them from hanging around until they emerge. It is dangerous for butterfly to have a bunch of males crawling all over it when it emerges. Later when males mate, they physically transfer some of this pheromone to the female.