The house martins are back, building nests above my study window. Last year they made a revolting mess down the window during the time my son was staying with me, and had opened the window.
This year to prevent the birds nesting in the same place, he trapped a plastic carrier bag through the opening part of the window. Has it worked? Has it heck!
They have been having a whale of a time, flying backwards and forwards building their little homes!
I shall not be opening the window, and hope the mess is minimal.
After the babies had flown, my neighbour used a telescopc pole to remove the detritus and the nests, it appears the birds have good memories.