The Dark World Of Dolphins (five); What The Ancients Did For Us (BBC2): I BLAME Flipper. Because of that marine TV star, we regard dolphins as gentle sea creatures eager to please and perform. The truth would appear to be different.

Watching The Dark World Of Dolphins was like discovering your budgie was a bird of prey or the cat curled up on your lap was a tiger. Violence, the experts assured us, is a daily part of life for these sea creatures.

They're not as menacing as sharks. Dolphins can attack people, not for food, but in self-defence. Remember that the next time you feel the urge to swim with dolphins.

Dolphins are more like us than we realise, exhibiting a range of behaviour like our own species. As British marine biologist Andy Williams reminded us, they are wild animals.

They use a vast array of hunting techniques. Footage showed dolphins skimming through the shallows like a surf board to catch fish. In an ocean estuary in South Carolina, a co-ordinated attack by bottle-nosed dolphins drove schools of fish ashore so they could snack on them. They hunt in packs, evidenced by eye-boggling film of a group of dolphins rounding up and eating a swirling mass of anchovies.

Dolphins are also violent towards each other, with scars on their bodies bearing witness to what were described as "aggressive interactions".

Sex leads males to attempt to prove themselves the dominant ones. If you happen to see a male dolphin trying to mount a female or indulging in penis rubbing, you'll be pleased to know this isn't about casual sex but part of the mating ritual.

Males act aggressively to keep their chosen female with them. They form alliances with other dolphins to stop rivals kidnapping or attacking their dolphin girlfriends. Partner swapping takes place to keep everyone happy.

I'll never be able to watch Flipper in the same light again. Presenter Adam Hart-Davis had equally mind-boggling stories to relate as What The Ancients Did For Us travelled to India to look at, among other things, plastic surgery methods and how they took the rocket to new heights in warfare.

Hart-Davis insisted on demonstrating as many of the gadgets and techniques as he could, including testing an Indian lavatory and firing rockets armed with sword blades.

Reporter Jamie Darling undertook the less attractive tasks, such as having oil poured on his eyes to improve his sight. It worked, although he confessed it was painful and wasn't in a hurry to make another appointment.

Another assistant was selected to receive an ancient Indian preventive treatment for smallpox. Four little scratches were made on the arm and pus from the sores of a smallpox victim applied. Happily, Hart-Davis made do with glue from the make-up department.

It looked horrible but, he reported, saved millions of lives. Not a word, though, about how to treat wounds caused by aggressive dolphins.

Published: 17/03/2005