I built myself a nice new boat shed ... specifically so my boat would be under cover & kept clean & dry. This is a 'gallows post & beam' construction so open to front and one side (desirable for airflow)
This year a pair of swallows arrived .... and my boat & everything in the boat house is covered with bird crap .... I mean serious piles of it on top of all horizontal surface .... I had to staple temporary plastic sheeting on underside of trusses where the boat goes ... to minimize the crap ........... the sheet is now covered with it.
The little sods (and there are now 2 offspring with them) also take to perching on any part of the boat and crapping on it.
I am an animal & nature lover, but cannot put up with this next year ......... my wife has also lost patience, and today asked me to go shoot them they are making so much mess, all over the new drive and the cars as well.
I know they are supposed to have migrated in August ... seems message has not got to them, we are being dived bombed, and high speed fly-past's by the things whenever we are near.
Once they go I'll remove the nest and as much crap as I can ... but I need to stop them coming back .... any suggestions.
Best I have found via Google is to have a model owl ... near entrance, supposed to keep them away.
(Maybe I should tie our cat to a rafter .... it serves no purpose in life, and just costs money to feed. )