We speak to a psychologist about the habit at the centre of the coronavirus spread.
Key charts and maps explaining how the respiratory virus has spread around the world.
Research is at an early stage but scientists said it had huge potential for destroying cancers.
It's 50 years since Moneta Sleet became the first African American to win a Pulitzer for journalism.
Around a fifth of people may be carrying the bacterium linked to some cancer cases, say researchers.
The virus emerged in December, two people have died and it has been detected in three countries.
Study shows the vaccine is safe, but it is still too soon to know if it can stop people from being infected.
There are millions of creatures, flora and fauna stored at the National Wildlife Property Repository in Colorado
Hundreds of people are ordered into coronavirus isolation with one of Australia's cutest marsupials.
The traditional cherry blossom viewing, or hanami, season is hugely economically and culturally important.
How are people with obsessive compulsive disorder (OCD) coping during the coronavirus outbreak?
Your internet-connected baby monitor or security camera could be being watched, officials warn.
The deaths have occurred close to the city of Seattle and are the only Covid-19 fatalities on US soil.
Briton Matt Raw, who was flown out of Wuhan, shows the BBC his living quarters at Arrowe Park Hospital.
As World War Two was ending the leaders of the UK, US and USSR met to plan post-war peace.
The former couple briefly reunite backstage after receiving prizes from the Screen Actors Guild.