Why flies can drink and drink

Hidden plumbing pumps fluids

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Try sucking maple syrup through a straw, and you’ll appreciate a fruit fly’s struggle to get a sip of sugar water. But a tiny system of valves and tubes works to pump fluid into a fly’s gut, researchers saw in the first X-ray videos of the insects slurping.

Scientists expected that pumping fluid would be more difficult for the fly as its gut swells up, the way inflating a bike tire requires more work as it fills with air.