For ticks, mealtime is an extended affair. The arachnid parasites latch on to hosts for days at a time. To find out exactly how ticks penetrate and anchor into the skin of their hosts, researchers examined tick mouthparts under microscopes and watched as the parasites attached themselves to the ears of mice.
As they report in the journal Proceedings of the Royal Society B, ticks first burrow into the host's skin with two telescoping, barbed structures called chelicerae. They then perform a breaststroke maneuver with the chelicerae, spreading them like arms and pulling them back. That motion sinks a spiky, swordlike appendage into the host. Positioned alongside the chelicerae, the shaft, called a hypostome, forms a tube for withdrawing blood.
Peering at a tick with a scanning electron microscope, “you can almost fly into its mouth and right into its midgut, like one of those red blood cells they're sucking up,” says lead study author Dania Richter, who conducted the research at Charité University Hospital in Berlin.