This experiment is one that we used for teaching about birds back when I worked in the Education Department at the Memphis Pink Palace Museum. On our trip, we went by to say Hi to old friends, which brought back tons of great memories. This is one of the fun things my brain dredged up.
Look at some bird nests. You can either search your yard ( just look, don't touch or bother the nest), visit your local Nature Center, or search the Internet. A quick Google Image search for "bird nest" came up with over 175,000 images of bird nests. Look at the wide variety of nests, from huge Bald Eagle nests that can weigh more than a ton, to the marvelous nests that Hummingbirds build from spider webs. They truly are amazing, but how hard are they to build. That is what we will find out.