Small

I am so small inside this big house
for here I am a little furry mouse.
My fur is shiny and the intent
is to keep me warm and the portent.
I'm a nocturnal creature and out at night,
as I do not want to give humans a fright.
How can anyone scream and others cry
for I am harmless, so sayeth I.
If you catch me in a humane trap
please put me outside in the rain.
I thank you ahead, if this happens to me
and hope that you will set me free.