Elusive supermouse refuses to take the bait

It sidesteps traps that would spell death for ordinary mice. It evades capture by scientists bent on its destruction.

This is supermouse, a rodent more likely to have originated in the centre of Birmingham than on the planet Krypton, but revealed to have powers beyond those of the average house mouse.

It refuses to be lured into traditional box traps and turns up its nose at cereals laced with poison, consumed with zest by inferior examples of the species.

This has led Rentokil, which is funding a research programme at Reading University, to fear that the mice have learnt to identify, and so avoid, the poison.

First scientists had to get hold of a supermouse to study it more closely. The mice were first reported six years ago and, in the early stages, one researcher failed for more than a year to catch a single one. Finally, teams of four or five scientists staked out factories and warehouses for days at a time, and caught the rodents by hand. It is not unknown for mice to be taught 'clever tricks' in laboratories by college professors studying behavioural patterns.

But Adrian Meehan, Rentokil's chief biologist, dismissed any idea that supermice were related to university-educated rodents on the run. 'Either there's been a genetic mutation, which has affected behaviour, or young mice are being taught by parents to avoid traps,' he said.

He said Rentokil had developed new traps which were being used successfully in the parts of Birmingham where the mice have been found. But he wanted research to continue until further evidence of their origin is discovered. This could prove useful should further strains appear.

However, one deterrent is as effective with supermice as it has been with their predecessors - the good old-fashioned house cat. But Mr Meehan said this was no solution for many storage companies. 'Cat droppings are even bigger than mouse droppings. Environmental health officers would have something to say about that.'