Not the catholic kind, the bird kind. For the last few days, I have had a beautiful cardinal hanging out in my back yard. He is a beautiful bird. The last few mornings, he had decided to start "knocking" on my sliding glass door. He comes over and hovers outside the window and flies into the glass several times, and will keep it up for about 10 minutes until one of the dogs goes to the door to try to figure out where that noise is coming from. :shrug Any ideas if I should be concerned about this? And what he is doing? It isn't like the windows are really, really clean, he is flying into the area where there are a lot of noseprints.

Birds fly into windows cause they see their reflection. It must be mating season and he is trying to get rid of the other male bird
Try hanging a tinfoil pie plate outside from the middle of the door

Thanks Bonnie, a good suggestion. I just couldn't figure out what he was doing.

Are you sure he isn't someones bird. Tame I mean. Have you tried to go outside and see if he will stay when you are out there. Hmmm, sounds like an angle is visiting you. Ever think of that. I have the doves right now and oh they are so pretty.

My sister had the same problem with a robin last year. Sorry, but she never found a solution and he hung around all summer. He woke her up quite often tapping on her bedroom window and tapped on all different windows around the house. I'm not sure if he has returned this spring - I'll have to ask her!