DD is very interested in field biology, so she was all excited about science fair (next year)--till we learned that it is virtually impossible to get approval of any project involving live organisms, even just observation in the field. If that is incorrect, please let me know, but this is what we have been told.
My local school district requires special approval if for use of humans or animals. And if you "question" other students as your test subjects you must get their parental approval. It believe it's just the students science teacher who approves these applications. They don't allow anything that would harm the animal, and err on the side of rejecting it if it could at all hurt the animal.
I have seen approvals for projects that include observations of birds in the wild, behavior of dogs, behavior of people. My son did his 6th grade science project testing hearing.
As for other live organisms. I don't think there is a prohibition, but I do know my kid's science teachers discouraged projects that involved growing plants partly because of time constraints. And partly their past experience with students projects that failed to grow at all.
