When a rooster mates a hen, his injected semen is stored in numerous sperm storage tubules (SSTs) located in the area where the hen’s uterus joins the vagina. That is, provided the hen likes the rooster. If she doesn’t, she can squirt out the semen to avoid hatching his offspring.

https://blog.cacklehatchery.com/how-long-after-mating-does-a-hen-lay-fertile-eggs/

@cowanon Imagine if humans evolved the ability to voluntarily control our reproduction? Things would be a lot different.