Cats and dogs may rule the roost. But Britain's pet-lovers are flirting with such an unusual group of other creatures that Puss and Rover would get a very nasty shock.

Chameleons, snakes, crustaceans, spiders are all gaining in popularity. And the quiet revolution in the country's pet shops is at least partly due to people's changing lifestyles.

Cats and dogs: favourites by a whisker

Mutts and moggies - still the most popular pets in the UK with estimated populations of 6.5 million and 7.7 million respectively - just don't fit in very well with many working people who live alone, or with working couples.

Which is where the more low-maintenance pets come in. A very 1990s way of sharing that bond between pet and owner - something the organisers of National Pet Week are hoping to celebrate in a bid to promote animal welfare.

Animal houses

A trip to a modern pet shop shows how tastes have changed. Fur and feathers are outnumbered by scales. Four legs are replaced by eight, or even none.

One man who knows a thing or two about new age pets is Jason Mather, who works in a London pet shop.

"More and more people are coming in to buy exotic pets - only last week I sold six spiders, two snakes and four lizards and tens of tropical fish," says Jason.

The Red-Kneed Tarantula: Changes clothes in spectacular fashion

Tarantulas, boa constrictors, pythons, water dragon lizards, iguanas, chameleons - it is a colourful crowd, but not one for the faint-hearted.

Pythons can grow to 14ft and weigh in at six stone. Iguanas can be highly aggressive to menstruating women.

All of these animals shed their skins and the majority have to be fed a stomach churning diet. Dead rats and mice for the snakes. Locusts for the spiders and lizards.

There are distinct trends in tastes, Jason says. "Big snakes are a favourite with men. And the bigger the better."

The Water dragon lizard

And women go for hairy spiders like the red-kneed tarantula, which literally blows its top four times in its life, jumping out of its skin and leaving the shell intact.

And teenagers plump for lizards.

Pet shop manager Graham Tilley believes the buying habits of his customers give an insight into human character.

"Snakes are for the insular or self-absorbed. Spiders are liked by the cunning. Lizards are for the daring and tropical fish are for the closet show-off and gadget man," he says.

Extreme fish: fun for gadget man

Both men agree that the attraction of unusual pets has come about through change in lifestyles. But they warn that people should not actually think of these pets as being easy to care for. Many people find they are unable to cope and release them into the wild - which can cause havoc for the native wildlife.

Pet predictions

So what's next? Well, according to Jason, the next trend has already started - the educational pet.

Leaf Cutter Ants are a prime example. An ant colony will live happily without you. But as one of the most complex social insects in the world, they hold a fascinating attraction for owners.

Pests in their rainforest habitats, Leaf Cutter Ants are exported to Britain - good news for those of us looking for something new.

Triops: Just add water

From the guard at the door to the queen in the sanctuary, each ant knows its place. And in their tireless maintenance of their nest lies a lesson in work and living ethics for us all.

Triops, another up and coming pet, are crustaceans also known as tadpole shrimps. They are living pets from the age of the dinosaurs, which hatch when water is added to their eggs.

Mature triops are three centimetres long, orange-red and shrimp-like and best at home in a jam jar. They are especially good for children and hours of fun can be spent watching them sift sand for food.

When they die, their eggs can be dried out and left dormant until the next rainy day.

But if you still yearn for fur, there are always rats - apparently a particular favourite of women.

Karen is one such customer. Asked to explain the draw of the rat she says: "Having met enough of the human male variety, I thought it appropriate to get one as a pet. But unlike men they are clean, intelligent and very loving."

National Pet Week activities take place across Britain until 10 May.