Officials have been forced to remove all the mirrors from toilets at an arboretum - to prevent feisty swallows from attacking their reflections.
Male birds that live in trees at The National Arboretum in Westonbirt, Gloucestershire, believe they are fending off rivals in the mirrors.
Paul Cody, head of visitor attraction at the 600-acre site, said the mirrors would be replaced when the swallows leave the building in October.
"We have taken the decision to remove the toilet mirrors each spring for a number of years now to prevent the resident swallows from injuring or causing unnecessary stress to themselves," Mr Cody said.
There are around five swallow nests in the public toilet building at the arboretum.
The young chicks usually fledge within the first few weeks of July and use the building throughout the summer.