Cardinals and robins are both tiny birds that can cause quite a bit of nuisance if you aren’t careful. These little animals are going to tap on the glass on the windows and you might think that they are continuously attacking the glass frame too.
However, it’s important to understand just exactly why these birds tend to act this way.
Cardinals and robins are both generally small birds, and they are quite territorial. The cardinal is a passerine bird, and you might have seen it flying about in many different shades and colors.
However, it can be an unsettling experience when you notice these birds attacking your windows or trying to get in.
There have also been cases where cardinals and robins have flown straight into the glass panes and gotten injured. Understanding why these birds do this is important.
You need to understand that birds such as the cardinal or the robin are incredibly territorial, so when they see other birds of the same category flying about in their territory, they have an instinct to attack.
You also need to understand that the glass on your windows or your car simply act like mirrors for these birds. When they are able to see their own reflection, they get instantly hyped, thinking that there is someone else encroaching on their territory.
As a result of that, they immediately attack.
Territorial Behavior

So, we have established that the root of this behavior is caused by the territorial tendencies of these birds. When these birds choose a site for their nest, they consider the area surrounding the nest as their territory.
Furthermore, they tend to defend it in a vigorous manner. Depending on the species of the bird and its size, their tendency to defend it is also likely to vary.
You need to understand that this activity is likely going to become more frequent during the breeding season, as many of these birds are on guard and high alert during this period.
Usually, you will see this happen much more frequently from May through August, and then there’s likely to be a pause as the birds move to a new brood.
Can the Birds Sustain Injury?
While this behavior is all too common among the birds, you need to understand that it is not usually fatal. In most cases, you will just notice the robins, or the cardinals sitting on the windowsills, making an angry face (as they do), and tapping on the window with their beak.
They are going to fly away once they realize that they are unable to get through. But, you should know that constant tapping with the beak could lead to an injury. The bird is likely to injure its beak, which could prevent it from eating properly or feeding its younglings.
Therefore, it is important that you shoo the birds away as soon as you see this behavior.
What Can You Do?

You need to understand that these birds are incredibly persistent, and it’s going to be difficult for you to drive them away.
Once a bird realizes that it can see its reflection in your window, it’s going to return to that place and continue tapping again and again. They are very persistent, but there are quite a few steps that you can take to make sure that these birds do not end up injuring themselves.
For starters, the best thing to do would be to cover your windows when you don’t want the sunlight in. You can just draw the blinds, and this is going to prevent the shade or the reflection for the bird.
However, you also need to understand that these birds will begin to look for other reflective surfaces as well.
There have been reports of cardinals attacking up to 15 windows on the first and second stories of their house, simply because they could see a reflection. So, while it’s suitable to cover the windows, you should know that there’s not a whole lot that you can do about it.
Simply put, the best thing to do is wait. You have to give it a bit of time and wait out the breeding season because that is probably the time when their tendencies are going to be at an all-time high.
But, what if the bird is constantly attacking the window when you are trying to sleep?
It can be incredibly unnerving and difficult to fall asleep when you have a cardinal or a robin knocking on the window constantly. The best thing to do would be to cover the outside of the window.
Ideally, a decent plastic painter’s drop cloth will do the trick. It should be of a medium weight so it won’t just fall off. They are readily available at local home centers and hardware stores. You can put that on the window.
The cloudy plastic texture of the cloth is going to ensure that light enters the room.
However, it’s going to limit reflections on the window, so you don’t have to worry about the birds knocking on them constantly. You should consider attaching the top to the window, and let it float freely.
The flapping caused by the wind is also going to scare off the bird.
Birds on Cars
There are also going to be instances where the bird starts attacking your car. This is likely to happen because there are just so many reflective surfaces on cars.
In most cases, this isn’t a serious problem, but if you notice the persistent knocking and attacks, you might want to take appropriate steps to eliminate the reflection on the surfaces.
For instance, you can place opaque grocery bags over the side mirrors. Or, if you have retracting mirrors, you should make sure that the mirrors are completely closed when you turn off the car.
When you park the car in the night, it might be a wise idea to cover it with a sheet of tarp.
Or, if you have a garage at your house, it is highly recommended that you park the vehicle inside. The simple thing to do is to move the car outside of the bird’s territory, but if the bird calls your home its territory, it might be difficult for you to find a suitable solution.
That is why you should cover the car with a weighted sheet of tarp when you park it outside, or just park it in the garage. There’s not a whole lot that you can do about these birds attacking reflective surfaces, and the best thing to do is take preventive measures.
Remember, don’t leave the windows open, because there is a pretty strong chance that these birds are likely to fly in as well. If you see the cardinal’s nest around your property, you should always steer clear.
It might seem like a good idea to leave food out for the birds, but that’s not something that you want to do. They are perfectly capable of taking care of themselves, and you won’t have much to worry about once the breeding season comes to an end.
These are just a few tips to help you stop cardinals from attacking windows.
Ben has a bachelor’s degree in construction engineering. When not constructing or remodeling X-Ray Rooms, Cardiovascular Labs, and Pharmacies, you can find him at home with wife and two daughters. Outside of family, He loves grilling and barbequing on his Big Green Egg and Blackstone Griddle, as well as working on projects around the house.
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