BBC's new documentary Dolphins: Spy in the Pod has uncovered dolphins' naughty habit of "deliberately getting high" on the nerve toxins of puffer fish.

Apparently the footage shows the dolphins "carefully manipulating" a certain kind of puffer fish, which releases the toxin if provoked.

As with many other drugs, a large amount of the puffer fish's toxin can be deadly. However, a small amount can cause a narcotic "high".

The Independent report that in the documentary, the dolphins can be seen chewing the puffer fish, and passing it carefully between each other.