In case anyone asks, the *only* reason male cats have spines on the glans penis is to induce ovulation in females during copulation.

Like many mammals, cats go into "heat", but this is only one part of the estrous cycle. Estrous is divided into 4 parts: proestrus, estrus, metestrus, and diestrus. Heat refers to estrus, or sexual receptivity. Ovulation usually occurs during estrus.

Estrous is defined by a complex interaction of hormones: luteinizing hormone, follicle-stimulating hormone, and the female sex hormones estrogen and progesterone. This sex hormone cycle facilitates the development of an egg from a follicle into a mature ova.

For many mammals, the pituitary gland automatically creates the surge of luteinizing hormone (LH) that triggers ovulation, thereby facilitating possibility of fertilization. In cats, the body requires a neural reflex to release LH (a neural signal that triggers some response).

What creates this neural reflex, you ask? In cats, the neural reflex that signals the LH surge that facilitates ovulation originates in the vagina. The stimulation for this reflex: spines on the penis.

Ovulation takes several hours following LH surge, which is one reason cats mate so many times. Yes, the alley cat screaming you've probably heard can also be explained by this physical phenomena, as the rigidity of the spines is likely uncomfortable as they rake the vaginal wall.

Additionally, the number of follicles that ovulate seems to be related to the number of matings, with one mating not being adequate to stimulate ovulation.

And so, no, its a misnomer that spines on the glans penis are designed to "hold the female in place" or that causing trauma to the vaginal wall (bleeding) is what gets her pregnant.

Wild cats mate up to 50x a day to ensure successful ovulation, which is where the magic happens: sperm meets egg(s), fertilization occurs, and embryos attach to the wall of the uterine horn in their own membranes that look like tacos.

I know introducing cat tacos at this point feels like I'm burying the lede, but really I just want you to know that the spines on the glans penis are specifically designed to induce ovulation in female cats. Nothing else. They don't prevent escape, they cause a neural reflex.

ISN'T THAT NEAT