It all starts with a mosquito bite. When a hungry mosquito pierces someone’s skin to gorge herself, she also pumps in her saliva to stop the blood from clotting. Far too often, microscopic stowaways hiding in the insect’s salivary glands also make the trip, crossing over into the victim’s bloodstream to look for a new home. These serpentine parasites swim along the blood vessels, making their way to the liver and infecting liver cells within just a few minutes. They hide inside these cells for anywhere from a week to a month (or even several months, in some cases), copying their DNA and growing larger and larger as they prepare for the next stage of their life. Eventually, the growing mass breaks up. A swarm of single-celled parasites bursts out of the liver cells and into the blood; once there, they invade red blood cells, feeding on their haemoglobin and energy stores to fuel another reproductive burst which will infect more red blood cells. As the parasite spreads through the blood, the unfortunate host will start showing the symptoms of malaria — everything from headaches and joint pain to fever, vomiting, and even convulsions. When a mosquito bites an infected person, she sucks up the parasite as part of her bloody meal. The malaria parasite mates within the mosquito, going through several stages before producing the serpentine cells that migrate to the salivary glands, ready to start the entire cycle anew.