Biting flies are attracted to blue traps - we used AI to work out why

Flies which feast on blood - such as tsetse and horse flies - inflict painful bites and spread debilitating diseases among people and animals alike. So a lot of work has gone into designing the most efficient traps to control the populations of these flies.

Biting fly traps tend to be blue, because decades of field research has shown that such flies find this colour especially attractive. But it's never been clea