BRITAIN has been invaded by an insect so small that it is almost
impossible to see with the naked eye, but which could be a serious hazard if it
spreads from houses to hospitals. So far, there are three known infestations of
the ghost ant, Tapinoma melanocephalum, two in London and one in
Birmingham. 鈥淭his is a new problem, and we desperately need information on new
cases,鈥� says David Pinniger, a consultant entomologist based in
Berkshire.
Ghost ants were probably imported accidentally by tourists returning from
northern Florida, where the ants are common. They are known as 鈥済hosts鈥� because
when they run around on light surfaces, their transparent abdomens and legs seem
to vanish, leaving just the dark head and thorax visible. On darker surfaces,
all you see are pale patches moving about. 鈥淭hese are very strange animals,鈥�
says Pinniger.
Although the ants do not bite, the infestations can cause annoyance and
distress. 鈥淲hen disturbed, they have a very rapid circling run that can make you
dizzy,鈥� says Pinniger. And if they spread to hospitals, ghost ants could take
disease into sterile environments in the same way as the Pharaoh ants (
Monomorium pharaonis) with which they are sometimes confused.
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Pharaoh ants arrived in Britain from Africa in the 1950s and are now
considered a major pest, especially in hospitals. Just 2 millimetres long, they
can infiltrate the tiniest cracks and crevices, spreading disease-causing
bacteria into sterile environments. Pinniger says he has seen them in sterile
dressings, operating theatres and glucose drips. The big worry is that the even
smaller ghost ants, which are only 1.3 millimetres long, will be even more of a
problem if they spread.
鈥淚 would be reluctant to say they will overrun us, but given the right
conditions, they could certainly increase in frequency,鈥� says Pinniger. People
who suspect they are 鈥渉aunted鈥� should call their local authority, he says. One
clue that could help people to trace a nest is that the ants give off a smell of
rotting coconuts when disturbed or squashed.