A favorite pastime for us is to point out all the bird and squirrel nests we observe during walks in the neighborhood. We have several birdfeeder projects planned but we're also planning to make a bird nest helper.
If you've never made one, a bird nest helper is simply a bunch of string, hair, yarn, grass, and other materials that birds might use to build their nest. We found this fun and simple bird nest helper by Etsy seller maddyandme. Or do as we're doing and make something yourself using a mesh bag or something similar.
There are helpful tips that you should read before making a bird nest helper. Safety tips such as avoiding string longer than 3-4 inches and not offering plastic or nylon are important. You can read more about safety tips here.