Call from the night

[Owl]

A nice read, I liked the relaxed tone and curious element of love. I'd say one of the biggest things that I believe you should work on is making sure every line is of great value to your poem, otherwise its presence isn't really needed.

Call from the Night
The darkness beckons
silently in the silky night air.
Enveloping her body in a cloak,
hugging her as an old friend.
He whispers words into her ear:
escape, bliss, wonder.
And she thinks about going with him.

She wonders what it would feel like
to see the shadows trace
the veins on her arms. Something about the reference to veins always intrigues me-- I like the idea of shadows tracing them.
To feel frigid adrenaline So the idea of shadows on her arm causes her to feel a "frigid adrenaline"? I feel a disconnect here... it's hard to believe that anything "dark, cold, or comforting" would cause a frigid adrenaline rush. Do you think you could possibly help the reader better understand why she's feeling this way by such a seemingly tame event?
pump through her blood:
Dark, cold, comforting.
And she thinks about going with him.

He tells her of his years;
How he hides in the night. I feel this may confuse the reader, because you titled this "Call from the Night". Can "night" hide in the "night"? Even if it was referring to the "darkness" that you referred to within the first line of the first stanza, how could darkness "hide" in the night? The night is largely darkness, and usually does not need to be found. Does this girl live in a place that is usually not dark? An extremely lit city? I believe this may need some revision.
And she thinks it seems nice Every line should hold value to your poem, otherwise it doesn't need to be present. How does "And she thinks it seems nice", really add this poem's atmosphere? How does this line impact the reader? I don't believe it does either. Revision may be needed here.
To be submerged in the calm.
Loneliness chimes in:
Peace, tranquility, freedom.
And she thinks about going with him.

But dawn breaks and darkness cries.
She fears of losing her companion
But something tells her to stay. Something? What was that something? If this "something" is an important element of the story, then tell the reader what it is! If not, then you'd be better off simply saying that she wants to somehow "stay" with the darkness, even if it is just subconscious. Let this line be effective to the story, otherwise omit it.
She hears a soft murmur in her ear:
I love you. Interesting how the darkness loves her, but still runs away. She can never really "go" with him even then, can she? Interesting concept, I can see how that could parallel a certain type of "forbidden love".

Darkness runs away.