There's a classic episode of Star Trek from the 1960s, The Trouble with Tribbles, in which the crew of the Enterprise fall prey to a sweet-talking salesman who sells them a cuddly fluffy pet.
But the tribbles breed – boy how they breed. And soon they are eating the crew out of spaceship and home.
If the coypu catchers of East Anglia ever made the connection, as they sat wearily in their living rooms with a cup of tea, muddy boots in the hallway, it's hard to tell.
What's sure is there was little cute about our 'tribbles'. They too bred and bred, thwarting the attempts of the trappers to keep up with their booming numbers.
It had all looked so different a few years earlier. There were still plenty of voices who saw the South American rodent as a blessing rather than a curse.
After its escape from fur farms in the late 1930s it had taken to munching through rushes clogging up Broads waterways, thereby keeping them clear for boats. The debate ranged back and forth: Did they eat crops? Did they tunnel into riverbanks?
In an attempt to bring some science into the matter, Norfolk naturalist Dick Bagnall-Oakley kept some for six weeks and discovered they were 'hopeless' at burrowing. He found that they liked sugar beet best, followed by kale and other root crops, but didn't really care for potatoes. He argued that their crop-eating was more than outweighed by their usefulness in keeping those rivers weed-free.
It was an argument that was not going to cut any ice with local farmers, who became increasingly strident as the 1950s wore on. Soon they were banging on the doors of their local MPs and the Ministry of Agriculture, Fisheries and Food, demanding action, but the ministry told Major Anthony Buxton of Horsey Hall in 1956 that it had 'no plans' to bring in controls.
In 1958, the National Farmers' Union county meeting in Norwich asked the ministry to list them as pests because of damage to sugar beet near waterways. Suffolk NFU followed suit a few months later. But the EDP was still predicting that 'an all-out attack on coypu in Norfolk was unlikely', and people continued to write in claiming the damage reports were grossly exaggerated.
The public mood, though, was definitely turning the farmers' way. Farmer G Tallowin of Willow Farm, Hickling, spoke for many when he told the EDP how coypu had cleared three-quarters of an acre of beet from his land: 'They took them when the beet were about as big as your thumb. They went right along the line, pulling the little beet up. They bit off the root and left the leaf lying on the ground. Rabbits were never as bad as that.
'Two years ago I used to think they were pleasant animals. I even use to feed one near the Broad. Now I kill all I can.'
In 1960 the language took on a military hue, with a 'War on coypus' reported. They were soon killed in their thousands, or rather tens of thousands, aided by a 1962 Order under the Destructive Imported Animals Act which aimed to wipe out coypu and mink within five years.
But still the numbers grew. More than 100,000 were reported killed in the year to September 1962 in the East Suffolk and Norfolk River board area alone. Rabbit clearance societies were called in to help tackle the problem.
Meanwhile, in the decidedly non-Broads setting of the Jupiter Road industrial estate in Norwich, a new 'weapon' was being introduced. The Coypu Research Laboratory would spend years finding out as much as it could about the coypus' habits, even fitting them with radio transmitters so their movements could be tracked.
A massive publicity campaign was launched at the same time, using everything from local television to post office noticeboards to warn the public of 'the coypu menace'.
For a while, it looked the battle would be won quickly. The terrible winter of 1962-63 wiped out tens of thousands, with guns, traps and dogs accounting for thousands more. By February 1965 a campaign was being launched to clear Wroxham Broad, described as the coypus' 'last redoubt' – a claim which turned out to be wildly optimistic.
In the same year Coypu Control was set up, with five trappers working full time - in hindsight, simply not enough. In 1966 the £72,000 campaign had cleared 2,500 sq miles of Norfolk, Suffolk and parts of Cambridgeshire, way above MAFF expectations.
But still the coypu appeared. Every year saw upwards of a thousand trapped, giving the lie to reports of a battle won. Then a series of mild winters in the early 1970s saw numbers rocket once again. In 1973 there were 7,601 caught – more than six times the 1971 total.
By now the campaign, which was originally supposed to cost £12,000 a year over five years was up to £30,000 annually with no sign of it ending. Critics began to point out it cost £6 to wipe out each coypu, but no-one had ever actually worked out in monetary terms how much damage they were causing.
It was time for a fresh look. In 1977 the independent Coypu Strategy Group was set up to look at long-term control issues. In June the following year, a £1.7 million masterplan was unveiled to wipe out the coypu within ten years. Just as well, with Coypu Control reporting the rodents had developed an alarming new taste - cereals.
The bitter winter of 1978-79 accounted for seven out of ten of the surviving coypu, with lone males detected as far north as Grimsby and as far south as Foulness. By this time there were 11 trappers and ten scientists battling against them; in 1980 that was increased to 24 trappers and three foremen.
The end was – at last – drawing near for the orange-toothed invader. In 1985 the EDP even dared to ask 'Battle over coypu nearly won?' after 2,300 were killed the previous year. By the following year scientists estimated there were fewer than 20 adults left.
In 1987 the last colony found near St Neots in Cambridgeshire, and only a dozen were caught all year. In 1988 just two solitary males were reported - one at Barton Bendish, and one near Peterborough.
And so in January 1989 agriculture minister (and local MP) John MacGregor was able to declare that, at last, the coypu were gone for good. Each of the trappers was stood down, with a £20,000 bonus for their efforts.
The end of the story? Not quite. In December that year a male coypu was caught at Little Ouse at Feltwell, and there continued to be 40-50 possible 'sightings' each year for some time. But nothing ever came of them.
Coypus did live on in Norfolk for a while – but at Great Witchingham Wildlife Park. And unlike the dodgy fencing that had caused the trouble all those years before, this time round the critters were securely penned in.
And so the great coypu saga had, finally, drawn to a close, after 53 years and more than £2.5 million.
Trapper Alec Waller, whose small blue van Coypu Control van 'Fifi' was a familiar sight on the Broads, spoke for many in 1980 when he said: 'I don't do this because I'm bloodthirsty. I don't hate them, I'm just doing a job. After all, it all came about through man's greed and women's vanity.'
And it was a costly and painful reminder that messing with nature could end in more than just tears.
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