Rebecca, Good idea! It would be very durable and quick to install. My cardboard ones have sides, so if you figure out a way to do that with a tag I would be very interested in your result. With cardboard, I always put the "decorative" side toward the box so as not to possibly spook the birds. I think I would also do that with a tag and leave a 2.5-3 inch gap between the guard and the box. Please let me know how it turns out if you give it a try! I'm glad you started a new thread on this subject. The other one had gotten sooo absurd. That's partly why I resorted to Latin in that one. But Latin strains my brain and I am so glad to be typing in English again!

Suzanne, a spooker should always be installed after the first egg is laid, if possible. Once an egg appears, the pair is more bonded to the nestbox and less likely to abandon it. However, if the spooker is installed after the female begins incubating eggs, you must observe the box to make certain that the spooker is accepted and she reenters fairly quickly. You don't want to interrupt the incubation cycle. Kathy

Hey Anita, I thought that too until one day I watched my momma Bluebird go up under the wren guard on the Chickadee nestbox. She was getting a bug on the ground before that and must have seen the hole when she was on the ground. So while it may take a bird longer to find a nestbox with a wren guard I don't think it is fullproof to stop HOSP as they could easily find the hole too if on the ground or by observing another bird going in and out of the nestbox with a wren guard. Just my opinion really but that it how it seems anyway. Donna

I had to google to see what you are talking about as I've never used one. According to this link it needs to be 2-1/2 to 3" away from the opening. http://bluebirdnut.com/forums/topic/how-to-make-a-wren-guard-with-photos/