Here's a wonderful resource on the web I just found:
The website is called 'Hands-on Science ' and they have many resources- one of which is a free butterfly unit study that is very comprehensive and looks like a fun way to spend the summer.
I also went back to that amazing on-line museum exploratorium.com where you can watch an online dissection of a cow's eye and learn more about how eyes work. cool! I don't have any of those lying around here, so it's great to be able to see it virtually.
One more stop if you have time after all that fun: A live ant-cam. No, it's not watching Aunt Val as she roams through her house dancing to opera music while she dusts... it's real live bugs in their home. Pretty interesting! (they do have anther nature-cam, but it's flesh-eating beetles, and since it's breakfast time around here, I figured you didn't want to see that one)