The bugs prick animals with their hollow, needle-like mouthpart, or proboscis, which injects pain-blocking, anti-clotting chemicals. It’s 30 times thinner than standard syringe needles. Plus, the bugs are bigger than mosquitoes, so they can draw more blood and are easier to handle — the perfect syringe substitute.
To collect lynx blood, Jewgenow placed the bugs into mesh-lidded holes in large cork plates that lined the lynxes’ den floor. Whenever a lynx rested on a plate, the bugs feasted through the mesh. Jewgenow then collected the plates and extracted the blood from the insects’ swollen abdomens.
This system worked for years until the team developed the fecal pregnancy test it uses today. Who would have thought these little bloodsuckers could help endangered wildcats return to their European homes? Not the lynxes; they never felt a thing. And that was the point.
[This article originally appeared in print as "No Needles Necessary."]