Answer:
What type of house weighs the least?
I sleep by day, I fly by night. I have no feathers to aid my flight. What am I?
Open me, and you can't see me without a mirror. Close me and you can't see me at all. What am I?
When it comes to me, you go on red and stop on green. What am I?
I am a small paradise surrounded by dryness and heat.
No matter how little or how much you use me, you change me every month.