Let's begin with a couple of stories about animals.

• In a safari park in Scotland, a chimpanzee named Chippy stole the cell phone of a keeper. He didn't just stop at that though, but went on to press the right buttons to dial pre-programmed numbers on the same to call the warden of the facility.
• In Vancouver, Canada, a duck would tug the pants of a police officer and waddle to a sewer drain. This continued for some time. When the office finally followed it to the sewer drain, he found ducklings trapped in it.

Was it a sheer coincidence that the chimp dialed the correct numbers? Was it the mother's instinct that prompted the duck to seek help from a police officer? Well, one cannot overlook the fact that animals are smart and have the ability to do simple things that require thinking. The mirror test developed by Gordon Gallup Jr. in 1970 is one of the apt tools to measure intelligence in animals. The animals who passed this test, which stressed on self recognition, were chimpanzees, orangutans, gorillas, bottlenose dolphin, orcas, elephants, European Magpies, and pigs. Besides self recognition, the ability to understand emotions and language also play a crucial role in determining how smart an animal is. Believe it or not, pigs are smarter than dogs! They are not only the smartest animals on the planet, but also among the cleanest animals around. Yes, a pig will refuse to excrete anywhere near the area where he lives and eats. You can even train a pig just like a dog or cat. If you train it properly, it will move the cursor on your computer screen with its snout and even learn to distinguish between the scribbles it knew from those it saw for the first time. You can watch the movie 'Babe' to believe that pigs are smart. Crows are considered the smartest of all birds. They grab the title by topping the avian IQ scale. They can count, differentiate between complex shapes, and even carry out observational learning tasks. The New Caledonian Crow has been found to create knives to cut leaves and stalks of grass. Ravens are like crows, but a bit larger in size and with different vocalizations. Ravens throw clams, nuts, and shells on the road and wait for passing cars to run over them. This helps break the hard shells and they can enjoy the delicious treat inside. You can read the tale of the thirsty crow to clear your doubts. Despite what you may have thought about them all this while, rats are among the smartest animals on the planet. A rat's psychology is similar to that of humans and therefore, they are mostly used for lab experiments. Rats possess a mental ability called the metacognition seen only in humans and some primates. They can use their keen sense of smell and hearing to detect land mines and bombs. They can even identify human sputum samples containing tuberculosis bacteria. The rat is indeed a smart animal, as it can show signs of excitement, loss, stress, and even remorse. You should see the movie 'Ratatouille' to know how smart rats can really be. The African Grey parrot is a native of the West and Central African rainforest. It's a well-known fact that parrots can mimic human speech, but the African Grey parrots go a notch further. They can associate words and their meanings to form sentences. These parrots communicate with their own by resorting to songs, calls, and body language. They can mimic people as well as the other voices they hear in the house. When an African Grey parrot belonging to Mr. Yosuke Nakamura of Japan wounded itself and lost its way, he gave the name, full address, and even the phone number of his owner to the authorities, thus helping them to track Mr. Nakamura and return him. Elephants are the largest mammals on land. They have always been known for their wisdom and fantastic memory. They draw mental maps of the location of watering and feeding areas. They can get back to a feeding area they did not visit for many years. Their large ears and long trunks help them listen. They communicate with roars, trumpets, bellows, and even transmit sound through ground. Now, that's a long distance trunk call! They are one of the few animals to pass the mirror test and identify themselves as independent individuals. They can even paint, make music, and show emotions related to grief and loss. The elephant graveyards are still one of the most talked about legends around the world. All species of the cephalopod family, including octopi and squids, have incredible intelligence. The octopus is considered the smartest animal in the invertebrate group. Besides short-term and long-term memory, they have great learning abilities. They can even carry out problem solving. They are the masters of disguise and have a knack for mimicry. They will beat the Great Houdini in the art of escape. They also have very good eyesight and sense of touch. The Santa Monica Pier Aquarium got a firsthand experience of the smartness of an octopus, when it managed to turn a valve that led to hundreds of gallons of water to overflow! The bottlenose dolphin has a large brain. Its cerebral cortex and frontal lobe are about 40% bigger than that of humans. It helps this dolphin species earn a place in the list of world's top 10 smartest animals. Bottlenose dolphins have the ability to reason, plan, solve problems, learn form previous experiences, etc. These dolphins also display emotions of remorse for other species. When two Pygmy Sperm Whales were beached in New Zealand, a local dolphin named Moko led the pair through the sand bars to safety. Great going Moko! Who would have ever thought in their wildest dreams that the abundant pigeons will also make it to this list. These birds are intelligent enough to recognize a picture after several years. Also, they can identify themselves in the mirror and even differentiate between two objects. The Potia Labiata, also known as the White Mustached Portia, is native to Africa, Asia, and Australia. Scientists have called these spiders smart owing to their tendency to carry out problem-solving experiments in the labs. In the wild, they lure other spiders from their web by tapping on it to create an illusion of an insect getting caught in it and when the spider leaves to investigate, they quickly eat up their dinner. They are also known to plot their hunt. They will even wait for their prey to return, if they miss it. The planning and plotting clubbed with the ability to understand that their prey will return, shows how smart these spiders are. A squirrel loves to munch on a 'nut', but is no 'nut'. Squirrels have a stubborn nature and flawless memory. They are very clever; ask people whose bird feeders they raid now and then. They will go all the way to raid bird feeders, flower gardens, or any place where they can find food. They are well adapted to living alongside humans. The tendency to store food for winter also proves that they are smart enough to plan. In fact, some scientists are of the opinion that they have an advanced level of cunning. You may not find this list perfect, but you can't deny that it is appropriate. Animals have the urge to survive, and I feel if one has the urge to live, he or she automatically works on it. Humans rank first in the list of smartest animals, but we also win the title of being the most selfish, and that negates whatever browny points we score because of our superior gray cells.