Rhinoceroses
National Geographic has the answer: 15 feet. Even though rhinos can charge up to 30 miles per hour, they can't distinguish between a human and a tree at 15 feet. Unless rhinoceroses can clearly hear and smell you, they have no way of knowing where you are in physical space.
Chameleons have some of the strangest eyes on the planet, which are able to move independently of each other. This results in almost 360-degree vision.
Interestingly enough, in our versatile animal kingdom, there are multiple animals that are born blind. One of them is the eyeless shrimp, which only has light perception. Another one is the star-nosed mole, the fastest-eating mammal in the world, who uses touch as their main sensory organ.
Several ant species, such as army ants, spend the majority of their life underground and are completely blind. Ants with smaller eyes have a smaller visual field, while species with compound eyes, especially larger ones, have an expanded and better vision.
It is physically impossible for pigs to look up straight to the sky. It's the anatomy of their neck muscles and the spine that limits the movement of their head and restricts them to look totally upwards.
Snakes have poor eyesight compared to other reptiles, although they still see color and ultraviolet light. Snake eyelids are quite different from ours.
Today, only the jawless lampreys have four eyes, according to researchers at Senckenberg Research Institute in Germany. The third and fourth eyes refer to pineal and parapineal organs, eye-like photosensory structures on the top of the head that play key roles in orientation and in circadian and annual cycles.
The mantis shrimp's visual system is unique in the animal kingdom. Mantis shrimps, scientifically known as stomatopods, have compound eyes, a bit like a bee or a fly, made up of 10,000 small photoreceptive units.
Leech: The interior structure of a leech is divided into 32 different segments, each of which has its own brain.
While modern arachnids, like scorpions and spiders, do not possess these particular otherworldly features, there is a one remarkable physical feature that some modern scorpion species do possess–12 separate eyes.
Although chitons look very simple, these mollusks have a very sophisticated shell. Its outer layer contains up to 1000 tiny eyes, each a bit smaller than the period at the end of this sentence.
Hydras are the relatives of jellyfish with tentacles. You must have studied how hydras move using their tentacles. They use their tentacles to sting and hunt other smaller invertebrates in an aquatic environment. They do not have eyes but have the capability of responding to light.
Scallops have up to 100 very unique and specific eyes.
#8: Snakes are deaf
Although they lack eardrums, snakes possess inner ears which are able to pick up not only ground-borne vibrations but low frequency airborne sounds. They do have difficulty with sounds at a higher pitch.
Snakes are able to recognise and distinguish between humans and may recognise the scent of their owner as familiar or positive with time. However, snakes are unable to view humans as companions so cannot form a bond with their owner like other pets can.
Even though they can't see colors or far away objects, snakes have very good close-up vision. This means they can see things that are right in front of them very clearly. Their eyes are also very sensitive to movement, so they can easily spot their prey (or predators) from a distance.
The new research shows that dolphins have the longest memory yet known in any species other than people.
Some of the most commonly affected breeds are Dalmatians, Bull Terriers, Australian Cattle Dogs, English Setters, English Cocker Spaniels, Boston Terriers, and Parson Russell Terriers. Congenital deafness has been found in over 80 different breeds, but it may be found in any breed.
Some squids have been shown to detect sound using their statocysts, but, in general, cephalopods are deaf.
Polar bears are the animals that do worst in captivity. Carnivores such as polar bears, tigers, cheetahs, and lions are especially poorly suited for life in a zoo, according to a new study.
Pigs are gentle creatures with surprising intelligence. Studies have found they're smarter than dogs and even 3-year-old children! In the wild, pigs form small groups that typically include a few sows and their piglets.
Because their bodies evolved in a way to prioritize finding food, pigs necks don't bend enough to allow them to look up at the sky.