Life

How hummingbirds really work, the thermostat preferences of leeches, and cattle-sparing disease testing in this week’s news

Hummingbird tongue is a trap
Shaking up nearly two centuries of thinking about hummingbird tongues, new high-speed video shows that nectar actually does not fill a pair of grooves at the tip the same way any liquid rises through tiny capillaries. Instead, the tongue’s grooves change shape as the tongue pulls out of the nectar and traps the sip.