I have another suggestion that would be cheap ( I was a den mom for my 16 yr old many yrs ago) we took them on a nature hike with brown bags and had them pick up pretty leaves pine needles just stuff they found on the walk, then on the next meeting we made a placemat we glued all the stuff the boys found on a semi large peice of paper, and then laminated it, mine right now is still on the back part of my computer I see it everyday, that I am sitting here.

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Proud mom to 4 great boys Anthony20,Nicholas16,Michael4,Sean2