The hat is a great idea....here are some sites that might give you more ideas or ones that you can explore with your son together

http://www.naturepavilion.com/livekits.htm

http://www.uky.edu/Ag/Entomology/yth...fal01.htm#meat

http://bugclub.ifas.ufl.edu/Bug_Bytes/Bugbites.htm

http://www.petbugs.com/

http://www.bloomingtonwebguide.com/insect.htm