Answer:
You can never eat me for breakfast or lunch. What am I?
I am the kind of ant that's good at math.
What do you call a sleeping bull?
I go up, let out a load and then go back down. What am I?
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?
No matter how little or how much you use me, you change me every month.