These are the forces that keep the insect airborne and moving forwards (see right).

BBC: Footage reveals how insects use their bodies to hover

"By rewarding the person that uses the overhead bridge by moving forwards three spaces, slowly it begins to sink in, " she says.

CNN: Monopoly moves to Africa with Lagos edition

As the aircraft accelerates, the airspeed of a blade (and thus the amount of lift it provides) increases when that blade is moving forwards and decreases when it is moving backwards.

ECONOMIST: Chop, chop

Sumitomo, another Japanese firm, is moving forwards in Kazakhstan.

ECONOMIST: Rare earths

Since moving from Manchester City in 2009, Sturridge has struggled to make his mark in a Chelsea side that includes forwards Anelka, Didier Drogba, Florent Malouda and Solomon Kalou.

BBC: Chelsea striker Daniel Sturridge joins Bolton on loan