Scanning electron micrograph of the sting of a honey bee (Apis mellifera) in a human finger. The picture background shows ridged skin with sweat pores (small holes). The sting (blue) has penetrated the skin at the site of a sweat pore. The bee is out of frame, to top. The sting consists of two grooved slides, each with a barbed tip, that enclose the stylus which delivers the poison of the sting. In this picture only the smooth surface of the slides is visible. The barbs are under the victim's skin. The sting penetrates the skin by a sawing action of the barbs. The barbs may prevent the withdrawal of the sting; commonly when the victim is an animal, rather than another insect. In that case, the bee is fatally injured as it breaks free of its own stinging apparatus. The sting is a modified ovipositor; only female insects can sting. Worker honey bees are sterile females. Mag x40 at 10x8