1. Dolphins have specially adapted eyes, which means they can see very clearly out of the water and under the water. They have almost no sense of smell.
2. In the wild, Dolphins normally sleep with only one side of the brain and leave the other side active so they can still swim, breathe and be aware of predators.
3. Dolphins can make many different sounds. They communicate mainly with various combinations of Clicks, Whistles and Pulses.[singlepic id=154 w=320 h=240 float=center]
4. Dolphins mainly use echolocation for hunting and navigating by sensing the response of the clicks they emit. They have extremely good hearing.
5. Squid and fish are the dolphins’ favourite food. Pods of dolphins often hunt together to scare and group small fish together so they are easier to catch.
6. The Killer Whale (Orca) and the Pilot Whale, among others, are actually dolphins.
7. Dolphins are highly social and highly intelligent. They are known to use tools to catch prey and display playful behaviour and learning abilities. The fact they also communicate and collaborate with each other in the wild and also with humans in captivity is further evidence to support this.
8. Dolphins do not have many natural predators, the main one being sharks or in some cases larger dolphins. Dolphins also tend to suffer from various diseases, which can spread between dolphins quite easily. The greatest threat to dolphins are fishing nets and hunting. They are considered quite a delicacy in some Asian restaurants.
9. Dolphins and their interaction with humans is well documented because they can be trained and lead fruitful lives in captivity. They work together with humans for therapy, entertainment (in Dolphinariums like Sea World, television shows like Flipper and films like Free Willy) and have also reportedly been used by the military.
10. Some Dolphins can dive up to about 300 meters and jump about 6 meters out of the water. Some can swim up to 40 kph and some can hold their breath for up to 30 minutes.