Chimps are able to walk on just two feet like humans can, and they have had very good special awareness and intelligence. One of our unique features as humans in our ability to recognize ourselves. This also happens with chimps, one was watching himself on a live video and starting opening his mouth and doing unusual things, to help him distinguish that he was looking at himself. When faced with most situations, they wait to observe what is happening and that act accordingly based on pros and cons.
One study with chimps included putting a banana out of reach of the chimp, but giving him to sticks to try and get it. While each one individually was too short, together they were long enough. The chimpanzee was able to use his spatial intelligence to put them together and retrieve the banana.
Dolphins also may be able to communicate better than humans, because their main sense and their form of communication or both with noises. They use their clicks and noises to make a language of their own. Like chimpanzees, dolphins are able to recognize themselves when presented the opportunity. This shows a lot of their intelligence, reinforcing the fact that they have one of the largest brains out of all animals.
One experiment resulted in dolphins figuring out that they would get fish if they did specific or creative tasks. They then proceeded to do as much as they could to get the fish once they figured this out.
One common thread with intelligent animals is their ability to recognize themselves, something that one elephant named Happy was able to do. According to NBC, the only animals to do this are elephants, dolphins, and types of monkeys. Being one of three types of animals to do this puts them in the upper levels of intelligence.
They can communicate with one another through the vibrations they can create with their trunks. Elephants are the only non-water animals that communicate through these seismic signals. Like the chimpanzees, elephants often use tools to aid them in surviving.