I only remember few scenes from the movie. I am pretty sure the movie had the word “fort” or “fortress” in the title. It was about a group of kids who are camping in the forest. But they split into two groups and battle each other.
There is a scene where they collect leeches and try to sell them (yuck) . Also, the girl of one team adn the leader of the other team are dating secretly.
In one scene she saves a drowning bee and says that bees dont sting who saves them.
I haven’t seen this one, but it may be “I Declare War”. Trailer:
Coming in one year too late, but if you still haven’t found your movie, maybe try Canadian movie La Forteresse suspendue
http://www.imdb.com/title/tt0261697/?ref_=fn_al_tt_6