Employee was unloading cam frame bolts (approx. 45 lbs. each) from a plastic box supplied by the mine. He stepped into the box to reach the bolts and noticed a bite/sting on his leg. He keep working. Later the bite site became painful, swollen and abscessed. He reported this to his boss 9/3/14 and was instructed to go the occupational medial clinic 9/4/14.