Answer:
You may enter, but you may not come in. I have space, but no room, I have keys, but open no lock. What am I?
I am the home for feathery animals.
Which vehicle is spelled the same forwards and backwards?
I always go to bed with my shoes on.
I am pronounced as one letter written with three. I come in blue black brown or grey. Reverse me and I read the same either way.
No matter how little or how much you use me, you change me every month.