UK autumn influx of harmless ladybirds seeking shelter in homes

Homes across the United Kingdom have been inundated with large numbers of ladybirds this autumn, with residents reporting clusters of the beetles on windowsills, doorframes and inside rooms as the insects seek shelter for winter. The surge, widely observed over recent days in towns and cities including Birmingham, has prompted questions about why ladybirds appear to be "invading" houses and whether they pose any risk.

Entomologists and ecologists say the phenomenon is a normal seasonal behaviour. As temperatures fall the adult beetles enter a dormant state known as diapause, reducing their metabolism and seeking dark, sheltered sites to overwinter. "Ladybirds need somewhere to overwinter, so they will try and find a dark, sheltered spot to lie dormant during the colder months," an insect specialist said. The insects commonly cluster together in crevices, beneath bark, in leaf litter or, when those natural sites are scarce, in buildings. Older or poorly sealed windows and small gaps around frames provide easy entry points.

Scientists point to a couple of factors that may be amplifying sightings this year. A warm spring and summer boosted populations of aphids, the primary prey of...