Penis
Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.
Human interaction with cats
Cats can also come in several body types, ranging between two extremes:Because of their small size, domesticated house cats pose little physical danger to adult humans. However, in the USA cats inflict about 400,000 bites per year. This number represents about one in ten of all animal bites. Many cat bites will become infected, sometimes with serious consequences such as cat-scratch disease, or, more rarely, rabies. Cats may also pose a danger to pregnant women and immunosuppressed individuals, since their feces can transmit toxoplasmosis. A large percentage of cats are infected with this parasite, with infection rates ranging from around 40 to 60% in both domestic and stray cats worldwide. Research indicates a correlation between the parasite "Toxoplasma gondii", which sexually reproduces exclusively in cats, and numerous human psychiatric conditions, including OCD. The compulsive hoarding of cats, a symptom of obsessive compulsive disorder (OCD), has long been associated with "crazy cat ladies".