3D model, based on confocal laser scanning microscopy data, of the mouthparts of an American dog tick (Dermacentor variabilis). At centre is the hypostome, the piercing and sucking device. Either side of it are a pair of protective palps. Barbs on the hypostome anchor it in place while the tick is feeding. This parasite is a vector for several human diseases, including Rocky Mountain spotted fever and tick paralysis. It carries the causative organisms of these diseases, transmitting them to humans when it bites to drink human blood. Confocal laser scanning microscopy is an imaging technique that focuses a laser beam on or inside a sample, and produces an image from only the point in focus. The focal point can be scanned over the subject, allowing images of very thin layers of an object to be obtained, which can be combined in a computer to form a detailed 3D image.