Ability to communicate, problem-solving skills, and several other factors are taken into account while determining the intelligence levels in animals. With so many factors coming into play, it's difficult to come to a consensus with regards to a list of the 10 most intelligent or smartest animals. There can be is bound to be a difference of opinion on the inclusion and exclusion of certain species from this list. Chimpanzees Chimps top the list of the smartest animals in the world. Their method of communication and problem-solving abilities show that they are very intelligent. It has been found that they combine different symbols and create a sign language for communicating with each other. Chimpanzees are quite organized in various activities they perform. They prepare their own tools with the help of available materials and use them for hunting. Qualities like self-awareness, altruism, and empathy are also exhibited by them. Being territorial in nature, they even go on to exhibit behavioral traits like possession, invasion, etc. In terms of memory, chimpanzees are superior to humans. Social hierarchy is an important feature of the nature of chimps. In fact, the urge to move up the social hierarchy is also seen in them. Dolphin The use of advanced techniques of communication propels dolphins into this list. They communicate ideas and thoughts by resorting to clicking, whistling, or making sounds such as 'eee'. Apart from communicating efficiently, dolphins are known to be efficient hunters who set up traps to catch their prey. They follow instructions given by humans without any difficulty, and are also capable of solving puzzles and working in teams. Elephants Elephants have a highly developed brain. Of the numerous benefits of their sharp memory, the benefit of remembering their migratory path is by far the most important. Elephants also remember their friends and people who have been kind to them. Developed emotions and depth of understanding are important behavioral traits of these mammals. It has been observed that elephants mourn if any of their companion dies and even remember the location of the grave-site. Other important qualities possessed by elephants include compassion, empathy, and self-recognition. Rhesus Monkey Rhesus monkeys are capable of taking decisions, have a good memory, and an amazing ability of learning new things with ease. Even the face of these monkeys is expressive, such that humans can easily decipher the thoughts and feelings behind these expressions. Rhesus monkeys are highly social in nature, such that they even go to the extent of planning attacks together. Vocal systems of these monkeys are sophisticated. Experts though, suggest that there are many similarities in vocal systems of rhesus monkeys and humans. Rats It might come as a surprise for you, but rats do exhibit high levels of intelligence. Their sense of hearing and smell is highly developed. They even display emotions like joy, remorse, stress, loss, etc. Rats are used in testing and carrying out studies more than any other animal in the world. In a study presented in 2007, the mental ability called metacognition, which was until then only seen in humans and some primates, was observed in rats. Crows and Ravens Crows and ravens are said to be the most intelligent of all birds. Their intelligence is primarily highlighted by their ability to find food and, more importantly, avoid predators. These creatures are also able to count, distinguish between shapes, and use different tools. Understanding social hierarchy also makes them stand out from the rest. Ants Ants are known for their social and organized behavior. Their intelligence is best described as strategic and methodical. Territorial nature of ants is well-known. In the process of protecting their territory or while hunting, ants share responsibility and delegate work. Adaptation to changing environmental conditions is an important trait possessed by them. Apart from being intelligent and organized, ants are physically strong. They are capable of carrying 20 times their own weight. African Gray Parrot These parrots can imitate human speech and communicate through various calls and songs. They can be trained to converse with each other and perform different tasks. African gray parrots don't just imitate human speech, but also mimic household noises and other sounds. One particular specimen from Japan, for instance, is capable of identifying 50 different objects and numbers up to 6. North Pacific Giant Octopus The North Pacific giant octopus boasts of being the smartest invertebrate in the world. Problem-solving skills and observational learning are not alien for this cephalopod. It is also known for its exceptional memory. Camouflaging and ability to mimic are other important qualities of this species. Whales Highly social in nature, whales are equipped with the ability to communicate over long distances. Their social nature is at its best during hunting. They are excellent team players and together, they are capable of executing a particular strategy with great precision. They also exhibit emotions like grief and anger; the former being mostly observed in the case of the death of a family member.