BBC: “Night night, sleep tight, don’t let the bed-bugs bite”¦” It’s long been a favourite rhyme to send children off to sleep. But with experts warning of a worldwide bedbug pandemic, will any of us be able to sleep once we’ve turned out the light?, asks Tom de Castella. Vampire fiction may be all the rage. But the true bloodsuckers after twilight are not charismatic updates of Dracula but tiny insects living in our mattresses, headboards and pillows. Yes, bed-bugs are back with a …