A Changeling Grateful

Here they give me greeting,
House me warm within,
Break their bread and share it
With the heart of kin.

Here the ruddy hearth-light
Singes not a moth,
Gives a summer welcome
As a red rose doth.

I would leave a gift here
If I might: not I!--
Like a homeless laughter,
Vagrant wind gone by.
But while I am a glow-worm
I will shine and stay:
When I am a shadow . . .
I will creep away.