Whenever the tree foliage disappears, it exposes a bunch of what appears to be bird's nest. I thought they may be built by Robins, there's certainly a lot of them in my area.
Recently, I am beginning to think they may not be birds nest at all. I notice a squirrel has been picking up dry grass and then dumping them to a "bird" nest. Unless some bird has managed to contract squirrels to build them a nest, I am thinking that these are actually squirrel nests.
How do I tell squirrel nest from bird nest?