Figures released by Historic Scotland reveal that the Palace of Holyroodhouse in Edinburgh has made 16
pest-related callouts since 2010.
The palace is regularly affected by mice, ants and wasps, although the bill for dealing with the critters was a modest £4801.
Edinburgh Castle came second worst on the list with 11 call outs over the three year period to deal with their unwanted intruders which included mice, wasps and even a squirrel.
Stirling Castle spent the most on eradicating unwanted intruders - splashing out more than £1800 on controlling pigeons and wasps.
As well as spending the third highest amount at £1,104.50, Craigmillar Castle in Edinburgh also had the third most call outs –ten since 2010.
More than £51,000 has been spent on the 345 protected sites in the last three years to battle pest problems.
A spokesman for Historic Scotland said they take “the care and wellbeing” of their sites “very seriously”.
Edinburgh Council received 4722 calls about rats between 2004 and 2013.