Schiphol etched a fly into its urinals and cleaning costs fell — men aim at targets

the problem

Spillage made airport washrooms expensive to keep clean, and signage changed nothing

background

what everyone would do

Post a sign asking men to aim carefully, or tighten the cleaning schedule to keep up with the mess. Signage had already been tried and changed nothing, because the problem was never a lack of awareness that spillage was a nuisance — nobody reads a washroom sign and decides, mid-task, to concentrate harder on aim.

what they saw

Van Bedaf recognized that aiming isn't a decision men make consciously, it's a reflex triggered by whatever's in front of them. Nobody needs to be told to aim carefully if there's simply something to aim at — the fix wasn't persuading men to try harder, it was giving their existing, involuntary targeting instinct something to lock onto.

the move

A cleaning manager who remembered a barracks trick had a fly etched by the drain: give men something to aim at and they aim.

why it works

Without a visual target, aim defaults to careless because there's nothing drawing focus to a specific point. Placing a small, discrete mark directly over the drain recruits attention automatically and triggers an aiming reflex the same way any visible target does, which means the improved behavior doesn't require anyone to read an instruction, agree with it, or choose to comply — it happens before any conscious decision is involved. A fly specifically taps an existing 'aim at the pest' instinct that needs no explanation, unlike a sign, which requires reading, understanding, and then deciding to act on it.

the payoff

Spillage reportedly fell ~80% and cleaning costs ~8% (the figures are 'very empirical', by their own admission). Thaler's favourite nudge; copied worldwide.

where it breaks

The target only helps if it's placed exactly where aim actually needs correcting — a mark in the wrong spot can pull aim toward a worse point instead of a better one. It also only works when the underlying problem is genuinely about where attention lands, not about fixture design, height, or angle that no target can compensate for. And the effect likely fades with familiarity or gets undone if the mark wears off or is cleaned away, which is part of why the team itself called the original spill-reduction figures 'very empirical' rather than rigorously isolated from everything else changing during the same renovation.

what came after

Richard Thaler calls it his favourite illustration of a nudge — make the right thing easier rather than the wrong thing impossible. The 80% spill reduction was, by the team's own admission, 'very empirical'; the fly conquered the world's airports anyway, and urinal targets are now an industry.

references

1. [1]Aiming to reduce cleaning costsWorks That Work (Blake Evans-Pritchard), 2013worksthatwork.com
2. [2]How a picture of a fly reduced washroom cleaning costs by 8%The Decision Lab, 2021thedecisionlab.com

keep it

same kind of clever

• 2000 · AIGA Design for DemocracyAfter Florida's 'butterfly ballot' cost thousands of voters their intended vote, the people who fixed it weren't election lawyers — they were typographers.
• 2001 · Richard Ankrom / CaltransAn artist tired of missing his exit built a Caltrans-perfect sign and installed it himself
• 2017 · Behavioural Economics Team of the Australian Government (BETA) / Australian Taxation OfficeAustralia's tax office cut inflated deduction claims by writing to the accountant, not the taxpayer