Christmas could be ruined by a plague of 'alien' moths invading the UK - and killing crops of Brussels sprouts. Supplies of the vegetable are already running low after several farmers' festive crops ...

Native crayfish in the UK could be wiped out by a new marbled species which carries a deadly plague. And these alien invaders can reproduce in great numbers at great speed without mating - if just one ...

Aliens could be spreading from planet to planet like a relentless plague, hitching rides on meteorites and ‘infecting’ new worlds like an epidemic on Earth. But if they are, we can spot them, experts ...