The beetles are 8 to 10 millimeters (males) or 10 millimeters (females) long. On the neck shield, which protrudes above the head, they have two large, transparent window stains through which the dark complex eyes shine. The males have a similarity to the large firefly (Lampyris noctiluca), whose neck shield has no window stains. Males and females of Lamprohiza splendidula can be easily distinguished from one another: the female has only extremely short wing stubs, so that the abdominal segmentation is visible and therefore looks like a larva. The female body is cream-colored and translucent, so that some organs shine through. This transparency of the body enables the light to shine through from the underside of the body, where the luminous organs are located. In the evening, the light of the flightless females living on the ground can attract the males. The German name glow-worm goes back to the larval-like shape and the luminosity of the female. The males have fully trained and functional wings. Her body is flattened laterally, the neck shield and forewings are gray-black. They stand on the sides of the body and cover the legs during the day. In contrast to the females, the males have only two light organs on the abdominal side of the abdomen, which stand out due to their cream-colored color. The males of the Little Firefly are the only nocturnal animals in Germany that can fly and shine. Eggs, larvae and pupae also have luminous organs.