To say I have a problem with barn swallows is a bit of an understatement. I have been at serious war with them since I have moved into this house 6 years ago. Last year I finally found a way to outsmart them. I put duck tape over all my doorways and on top of my fan and light fixtures. Success, no bird nests. A few birds may or may not have accidentally caught themselves on the tape but I am not a savage, I spared their lives.