The mosquito truly is a blood-sucking machine. The thin tube the insect injects into the skin, what's called the proboscis, is actually comprised of six different needles that all work in tandem to extract blood from the body. It's fascinating and repulsive at the same time — and it's described perfectly in a new episode of Deep Look, a YouTube video series produced by KQED San Francisco.
Fascinating and repulsive at the same time
The first two needles act a bit like teeth, the video shows. The have tiny ridges at the end that help the mosquito puncture through the skin. A second pair of needles act like clamps during the blood draw, holding the skin's tissues apart to allow the last set of needles to do their work. Among these is a needle that acts like a homing beacon; it finds our blood vessels by detecting the chemicals they give off, and then slurps up the tasty blood inside. The last needle is the real jerk: it injects chemicals into our vessels to stimulate blood flow. But it's also what makes those itchy bumps appear after the mosquito gets its fill and leaves. All of these needles are then shielded by a flexible sheath called the labium.
It's during this process that the mosquito can spread infection. When these insects take up our blood, they also leave behind traces of their own saliva. That saliva can contain viruses that get into our blood vessels, causing severe illnesses like dengue, West Nile virus, Zika, and chikungunya.
I hope the people whose skin was bitten in the episode got a hefty bonus for their performances. But the best part of this video has to be its liberal use of sound effects. Any time a mosquito is shown sucking on the skin, there's audio of what sounds like someone smacking their extra moist lips. It helps you grow even more disgusted, in case the thought of a mosquito siphoning up your insides through a straw wasn't gross enough.