WindowAlert UV Liquid Marker | Anti-Collision Bird Deterrent to Prevent Bird Strikes on Windows and Glass Doors | Protect Wild Birds Around Homes and Buildings

Don’t use unless you want to have your windows locked like a Christmas tree.

Did nothing to decrease the repetitive and numerous (over 100 a day) hits that a local cardinal is making on our window.

We have many windows on our covered porch, and birds make it a point to run beak-first into the glass. I was skeptical that using this bingo-like marker would accomplish anything, but it worked great immediately. The key is to make sure and space the dots close together. I placed dots within 2" of another dot. The UV dots do not obstruct my views. I can see them, but they are much better than using more obstructive stickers. I have had no bird strikes since covering my windows with the dots.Note -- when you wash your windows, you will need to reapply the dots. I am fine with that.

This is a convenient product with the large marker rather than using a regular UV marker. It's easy to oversaturate the felt, though, resulting in drips for the first few applications, so it's probably best to let it sit upright for awhile after wetting it before use. You can see the dots from the texture of the dried liquid, but it isn't too bad.There haven't been any bird strikes since applying it on the inside of a sliding glass door that faces a feeder. The birds seem to see the dots. A dove flew over and tried to hover by the door to presumably look at the dots and a Junko perched on a chair in front of the door the next day and seemed to examine the lowest line of dots. Hopefully this product keeps my feeder birds safe.

I was willing to pay the price to save the lives of birds and not have stickers or solid stripes all over my windows. During migrating seasons, we have bird strikes weekly and we lose 1-2 birds each year. I needed to do something! Putting a few things on our windows did not solve the problem. So gave this a try. I read the reviews and used a craft foam brush to apply vertical lines 3-4" apart on my windows. This was a bit of a process of daubing the bottle onto the brush and then applying to the window when it is difficult to see the line. It dried quickly and when you glance out the window, you don't see the lines. If you inspect the window carefully, you definitely can see them. The week after I applied I had another bird hit the window, but none after that. So it did not work perfectly, but I cannot say definitively if it did not work well. We might have had several more bird strikes without it or we might not have. The real test will be next spring when I reapply prior to migrating season.

You can see from the photo that we have an enormous expanse of windows - and we have suffered from bird strikes after we cleaned our windows. This past spring during quarantine, we realized we were having non-lethal strikes once or several times every day, and lethal strikes every other week, terribly sad all around. I was struggling with what to do- I did not want to put glitter stickers or some other tacky option over the nice windows and disrupt the view and aesthetic, but I couldn't keep hearing a bird smash into our window and having to go over to see if it had a broken neck or not. I tried this UV liquid, and tried something that is not on the bottle's instructions. Instead of putting polka dots all over my windows, I instead painted the liquid over the window frames. I hoped that by outlining the glass panes with the bright UV reflection, it would look different enough to them that they wouldn't fly right into the window. It dries clear, you can't tell where I put it- I do have grey paint on my window frames. I waited 3 weeks after painting the window frames to write my review: It Works! I have had no strikes in 21 days. We are still home all day, and my wife has commented on the well it is helping. If you have birds hitting your windows-It is worth a shot. Its not too expensive- it has to be redone every few months so be prepared for that, but it doesn't take long. I have been very happy that I can have my windows and keep the birds safe. Will use from now on.

Updated 11/2024 - it’s been over a year and several cleanings but you can still see dot residue on the windows. There’s no UV reflection left but it’s almost like this stuff burned itself into my glass. Really hate that I decided to use this and that I ended up with dots that serve no purpose now permanently on my windows.So these work if placed properly. The first application, I applied randomly like the photo but that didn’t stop collisions. I also didn’t realize how quickly the UV wore off especially when exposed to rain and sun. Once I put them on in a uniform pattern, closer together, it pretty much stopped all collisions except if a bird would be randomly startled. If you are diligent about placement and reapplying, it does its job. Also, the farther you place dots, the more likely a bird thinks it can fit through the space between the dots - so the closer the dots, the number of collisions should decrease.This DOES NOT stop territorial aggression. Some reviews talk about birds coming up to the window and pecking at the window. That is not a collision. This product works for collisions, and does not make the window reflection completely invisible to birds. You have to get special products for territorial aggression (screens do usually work to stop that).