...they use their tongues like sponges! According to my book, the forked tips
of hummingbird tongues "are often fringed and contain central grooves or channels."
A drinking bird extends its tongue into the nectar. Then it draws its tongue in,
closes its bill, and pushes the tongue outward against the inside of the bill.
The nectar is squeezed out (the same principle as a sponge mop) and then swallowed.
All this is done very rapidly, of course.

The books say that a female hummingbird feeds her nestlings in the morning
on nectar, to warm them with quick energy, and on insects in the afternoon.
I wonder how she feeds them on nectar? She must regurgitate it. The same
with the insects, I suppose, which would save her having to fly back and forth
so often to the nest.