   OK. So imagine this. It's a hot day. Someone offers you a
cold lemonade. But there's one condition. You can drink it only
using your tongue. No lips touching the glass, no straw. It's
what bees, butterflies, and hummingbirds do when they slurp
nectar from flowers. And now scientists have discovered a
species of bat whose tongue is also a particularly fancy nectar
scoop. NPR's Rhitu Chatterjee reports.  RHITU CHATTERJEE,
BYLINE: The bats live in Central and South America. They're
roughly two inches long and they spend their nights going from
flower to flower.  CALLY HARPER: They hover for just a few
seconds in font of the flower corolla and then they probe their
tongue deep into the base of the flower tube and soak up nectar.
CHATTERJEE: Cally Harper is at Brown University and an author of
the new study. She says when the bat sticks its tongue out, that
tongue is about twice the length of the animal's head.  HARPER:
Its common name is the Pallas' long-tongued bat.  CHATTERJEE:
Now the challenge for all nec