Leopard cat

　　We know that cats hunting mice is their nature. This is common knowledge taught in books or classrooms before. When there is a rodent problem at home, we can also let cats catch mice. But have we ever thought about why cats like to eat mice?

　　For cats to hunt mice, we first need to start with their eyes. When we observe cats, we often find their eyes very spirited, like a precious gem. Moreover, their eyes can change the shape of their pupils with the alternation of day and night. In the dark night, their shining eyes add a touch of mystery to the silent night. However, cats' vision during the day is much worse than humans'. Because cat eyes have an extraordinary ability to collect light, along with their high-performance hearing and amazing concentration, cats can see things even in the dark night. It can be said that the darker the light, the clearer cats see. The reason cats can have good vision in the dark is that they have a developed cornea; their curved lens is much larger than humans', so the lens’s corneal position is closer to the retina. To make the light focus precisely, both curvatures increase, of course collecting more light.

　　In recent years, scientists found that cats have a substance called taurine in their bodies. Taurine is a white or colorless oblique crystal, mainly distributed in animal nerves, muscles, and glands. Taurine is the chemical that enhances cats' night vision ability. Experiments show that cats lacking taurine have widespread degeneration of rod and cone cells in their retinas. Since cats cannot synthesize taurine themselves, they must consume a large number of mice to maintain enough taurine in their bodies, thus preserving sharp night vision to survive in fierce natural competition. This is why cats have long had the instinct to hunt mice.

　　From another perspective, why can cats become expert mouse hunters? Is it just because their vision is good? Scientists discovered that cats’ bodies carry a kind of parasite that can cause abnormal behavior in mice. This parasite resides in the cat’s intestines and is excreted through feces. Infected mice change their behavior towards cats, and then cats eat the mice, ending the parasite’s life cycle. Scientists also say this parasite is a very strange organism; if they can increase the chances of completing their life cycle, they undoubtedly will do so. This parasite has a two-stage life cycle, meaning it has at least two hosts. Mice are one intermediate host, and cats are another host. This parasite even changes the behavior of mice, making them more likely to be eaten by their main host, cats.

　　These parasites in mice and cats are harmful. Research shows they invade the nervous system or brain, and can even affect the human brain. Although cats can catch mice, eating raw mice is very frightening; mice carry many bacteria and viruses, and careless contact can cause infections. So, generally, it is better to keep our pet cats away from mice. (Source：PetsZone)