Ringing a doorbell in the middle of night might not seem an impressive achievement when you have two stomachs, can clone yourself and your biggest colony stretches across 3,700 miles.

But a nest of ants terrified a 75-year-old woman in the German town of Offenburg who called the police at 3am after her doorbell repeatedly rang. Officers discovered the culprit was a nest of ants who had built a home of such size it pressed elements together to work the switch.

The species of ant was not revealed (there are 12,000 vastly different ant species known to science and perhaps 90,000 still to be discovered) but one suspect is the pharaoh ant, named according to one legend because Linnaeus found it in a mummy.

This warmth-loving insect can only survive in northern Europe with help from humans and appears attracted to electric currents, perhaps because it can detect heat this way. The pharaoh has swarmed into hospitals and once bit babies in incubators in former East Germany.

Another power-crazed invader is Lasius neglectus, the Asian super ant: it was first found in Britain when 35,000 carcasses were discovered in one electrical junction box at Hidcote Manor in Gloucestershire. It appears to have a fatal attraction to electricity.

Ants' nests vary enormously between and even among species. Larger nests further north help ants keep warm: in Northumberland, hairy wood ants have made nests that are larger than the Empire State Building, relative to their size.

Experiments to learn more about these social creatures can be as ingenious as their miraculous lives. Dr Elva Robinson, Royal Society research fellow at York University, is studying how ants work together to choose nest sites by fitting tiny RFID tags to individual ants.

One of her research questions is why ants that spend their days foraging are leaner than "fat" ants who stay in the nest. Using radio tags, Robinson closed automatic doors on tagged individuals to prevent them from foraging. These lean foraging ants stayed lean during their confinement, which forced the fat ants out of the nest to look for food. When the doors were opened to the lean foragers again, they immediately resumed their role despite having no recent foraging experience.

These divisions of labour are incredibly logical, explains Robinson: the fat ants hold food in their crops and are a food store for the colony; the lean ants are highly skilled foragers. And if a lean ant perishes on its hazardous foraging missions, at least the colony doesn't lose the food stores found on a "fat" ant.

Robinson nicely explains the wonder of ants. "All the individuals are relatively simple but the sum of all their simple behaviours is way beyond what you could predict just by looking at the individual," she says. Just as the terrified German householder discovered when her doorbell rang.