After 180 years, we now know how hummingbirds drink.
"As the bird sticks its tongue out, it uses its beak to compress the two tubes at the tip, squeezing them flat. They momentarily stay compressed because the residual nectar inside them glues them in place. But when the tongue hits nectar, the liquid around it overwhelms whatever’s already inside. The tubes spring back to their original shape and nectar rushes into them.
The two tubes also separate from each other, giving the tongue a forked, snake-like appearance. And they unfurl, exposing a row of flaps along their long edges. It’s as if the entire tongue blooms opens, like the very flowers from which it drinks.
When the bird retracts its tongue, all of these changes reverse. The tubes roll back up as their flaps curl inward, trapping nectar in the process. And because the flaps at the very tip are shorter than those further back, they curl into a shape that’s similar to an ice-cream cone; this seals the nectar in. The tongue is what Rubega calls a nectar trap. It opens up as it immerses, and closes on its way out, physically grabbing a mouthful in the process." Click here to get the full story from The Atlantic.