PIGEONS caused havoc at a Stockley Park building - when they worked out how to use the revolving doors.
The birds orginally set up roost in the glass atrium of the building in Longwalk Road when it was under construction.
Builders thought they had seen the last of them when the front of the building was installed, complete with a set of revolving glass doors.
But staff at pharmaceutical company Celgene UK were mystified when they moved in, only to find the birds were still managing to get inside.
And once they were in they were doing what pigeons do best - making a mess - much to the misery of the staff and vistors who got caught in the line of fire.
It was only when bird controller Andy Dobbs from NBC Bird and Pest Solutions of Byron Way, Hayes, visited the property that he realised they had worked out how to use the revolving doors.
They had learned to hop on to the sensor, activating the doors, before calmly strutting through - and they were often queuing up to make their entrance.
The problem was solved by installing “fake fire gel” at the side of the doors, which gives off an ultra violet light and fools the birds into thinking they are walking towards a fire.