Revealed: secrets of life's weird rhythms

It sounds like Heaven for pub quiz enthusiasts and eight-year-old kids. Did you know that cows sleep standing up but only dream while lying down? Were you even dimly aware that the South Pacific Palolo worm mates only once a year, under a full moon in late October? Or that the Samoan people collect the eggs and sperm, and then bake them for an annual feast?

It sounds like Heaven for pub quiz enthusiasts and eight-year-old kids. Did you know that cows sleep standing up but only dream while lying down? Were you even dimly aware that the South Pacific Palolo worm mates only once a year, under a full moon in late October? Or that the Samoan people collect the eggs and sperm, and then bake them for an annual feast?

This year's showcase summer exhibition at London's Natural History Museum is a comprehensive tour of weird nature and perverse animal behaviour, answering the questions you always wanted to ask, and many more you didn't.

The Magicada cicada only emerges from its burrow once every 17 years. Aspidistras flower at night so they can be pollinated by slugs. Toads think loud rock music is a rain storm and a blast of Meatloaf gets them crawling out to the party.

The exhibition's chief researcher, Paul Bowers, insists there is a point to this chaotic tale of sleep and copulation, and that point is survival. Called the Rhythms of Life, the display attempts to demonstrate that the natural world is governed by millions of body clocks, without which life would collapse.

The results can be strange. "The ancestors of cows had to be on the look out for predators, so they have evolved to take short naps standing up, sensitive to any danger approaching them.

"Dream sleep is much deeper but if you dream standing up you will fall over because your muscles relax. Cows get around this by having their deep sleep lying down while surrounded by other cattle."

The same fear of attack is thought to explain why dolphins snooze with only half their brain, leaving the other half on guard for predators.

The principle of security in numbers explains the behaviour of another of nature's oddities, the Magicada cicada, a grub that stays under ground for 17 years before it rises up in a swarm of thousands, mates, lays its eggs and dies.

Why is a cod like a tree? How do you fool a European shore crab? Answers at the exhibition. Why did the chicken cross the road? The Natural History Museum is still working on it.

Rhythms of Life opens on Saturday 8 July.