In the 1980s, Darryl Gwynne and David Rentz were biologists on a field trip in the Australian bush.
By the side of the road, they noticed an unusually large beetle on an empty beer bottle.
They examined it and found it was a jewel beetle.
It was iridescent: its shell reflected different colours according to the angle of the light.
But while they studied it something else became apparent.
It had a large, erect penis and it was trying to have sex with the beer bottle.
They tried to brush it off, but it wouldn’t let go.
It just carried on trying to mate with the bottle.
As they looked around they could see more beer bottles everywhere, mainly "stubbies": short, squat bottles, brown in colour.
Australians tend to throw them out of the car window as they drive through the bush.
What surprised Gwynne and Rentz was that lots of these stubbies had jewel beetles attached to them.
None of the other bottles and cans, just the stubbies.
And not just randomly attached, all the beetles were clinging on while trying to have sex with the bottom of the bottles.
What made the bottom of stubby beer bottles so attractive?
Eventually it occurred to Gwynne and Rentz.
The female jewel beetle is much larger than the male, and covered in lots of little dimples.
In the sun, the brown glass glittered like the female shell.
And around the base of the stubbies was a ring of dimples, to make the bottle easier to grip.
The brown, dimpled stubbies looked like the most attractive female imaginable to the male beetles.
Their instinct overcame all the evidence to the contrary and they just couldn’t help themselves.
They clung on while Gwynne and Rentz tried to remove them.
They clung on even while ants began eating them, gnawing away at their exposed genitalia.
They clung on, trying to have sex with the beer bottles, until they died.
They clung on because they couldn’t give up on the illusion.
We may laugh but it isn’t so different from what we do.
We cling on to illusions despite all evidence to the contrary.
For instance, we cling onto the illusion that all marketing plans must include digital as their core component, no matter what.
We cling onto that despite any evidence to the contrary.
Despite the fact that Marc Pritchard, Procter & Gamble’s chief brand officer, says online media practice is "murky at best and fraudulent at worst."
Despite the fact that an independent review just showed 43% of mobile ad impressions are provably false.
(That’s a study of a billion impressions across a thousand mobile apps.)
Despite the fact that, in the US, the industry body is proudly touting that online ad fraud will drop from $7.2 billion to just $6.5 billion this year.
(Register that: $6.5 billion of fraud is hailed as something to be proud of.)
And despite the fact that we know the most powerful bots are capable of creating a billion false advertising impressions every minute.
But we don’t believe any of that, we can’t help it, the illusion is too strong.
How can this be a beer bottle, it looks just like Jessica Rabbit.
Dave Trott is the author of Creative Mischief, Predatory Thinking and One Plus One Equals Three.