Woodlice or slaters are actually terrestrial crustaceans.
They can be found in swarms around garden compost heaps.
Here is the species studied, Porcellio scaber in a variety of sizes and colours (probably the stage after moulting).
However, until a publication this week, invertebrates have been largely regarded as identical, almost automata.
One can't help thinking that Dr Tuf, on the left, has more than a passing interest in individuality and was predisposed to ask the question:
Do invertebrates display individual characteristics?
By posing a threat to woodlice (prodding) researchers were able to induce them to curl into a protective ball, armadillo-like. They called this state, Tonic Immobility.
They then recorded the time it took individuals to uncurl and start moving again. They found that different individuals were consistently quicker to curl up and others remained in that position for longer, indicating individual 'personality' differences in an invertebrate.
'We also identified personal behavioural patterns in all tested individuals, as well as variation within body size groups'
'Porcellio scaber is one of the first species of terrestrial isopod with documented personality traits'
Personality in animals has been defined as individual behavioural characteristics that are consistent over time in response to different situations.
Even taking account of influences such as body size, the wood lice display behaviours that meet the definition of 'personality', said the researchers.