It stands just 4cm tall and weighs less than a pencil but has the power to hold up a £20 million project and the movement of 450 University of St Andrews staff to new state-of-the-art offices.
In what is a major strategic move by the university, the former paper mill at Guardbridge is being transformed into a modern working environment for key professional staff.
Staff were due to start moving in December, but the plan has been delayed as a result of measures taken to avoid disturbing a bat and because of unforeseen issues with the existing building structures.
Contractors discovered two potential bat roosts at the north end of the former paper mill buildings being converted into modern offices at Eden Campus.
The bat species was identified as Common Pipistrelle.
Prior to works commencing a strategy was agreed to minimise disturbance to the roosts as work was continuing through the hibernation season.
This involved establishing exclusion zones around the roots to ensure that the bats were protected during hibernation.
Following the end of hibernation the roosts were inspected, confirmed as clear and sealed up.
The presence of the bat and some other unforeseen issues with the existing buildings at the Eden Campus site have resulted in a delay to the project of about eight weeks.
It is now expected that staff will start to move to Eden Campus in February next year.
The university plans to install eight bat boxes, four large roosting boxes and four multi-seasonal boxes at Eden Campus.