It is indeed a sad day when we find a hummer dead. However, I use scientific specimens all the time and I have the necessary federal and state permits to salvage dead birds to be used for the sake of increasing our knowledge. Otherwise, it is unlawful to possess and keep even so much as a feather, a fragment of egg shell, or a nest of any protected species.
First, you need to make a cone of plain white paper, typing paper will do nicely. Drop the bird in head first and the body will be held in a somewhat natural position. Place the cone in a heavy duty zip-loc freezer bag and freeze it. Meanwhile, on a plain piece of white paper, write your name, your address, the location the bird was found dead. Your street address will do, but map coordinates may be preferred. Add the date. Write in archival quality ink so that the ink does not run and stain the feathers. Place the slip of paper in the bag with the specimen.
Now, you need to find a natural history museum or college biology collection that will take the specimen, prepare it properly, and make it useful as a learning tool for generations to come. You cannot keep it legally and no licensed taxidermist can legally mount it for you.
I have been fortunate to have the fine facility and staff of the Louisiana State Museum of Natural Science at my disposal. Without their collection of preserved specimens, I could never have learned all that I know and I consider it a privilege to be able to educate others. Some of the specimens I use were prepared as early as 1880. This may be a good opportunity to teach your son about the science of ornithology. I met an 8 year old this morning that knows a lot about the giants in the field. They are never too young to learn.
Nancy L Newfield
Metairie, Louisiana USA
USDA Zone 9