I used to live with a guy who had no sense of smell – true story, but feel free to apply your own punchline. At the time, the cause of this phenomenon (known as anosmia) was unclear, but recent research indicates that my friend may simply have had an overabundance of ‘death factor’ cells in his nasal mucus.

However, mucus has its uses – in unnatural noses as well as the real thing. A group of UK scientists have discovered that furnishing their ‘electronic nose’ with a mix of polymers that replicate the function of human snot vastly improves the device’s ability to discern different scents.