Best riddles with simple answers

I had no father, only a grandfather. I shall bear no sons, only daughters. What am I?

There was a railroad crossing without any cars and trucks! Can you spell that without using any "R"?

What comes down but never goes up?

I am small. I can be scary. I have eight legs. I spin a web. What am I?

What do computer programmers sing in the shower?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth I am dissolved into air. What am I?

Slayer of regrets, old and new, sought by many, found by few. What am I?

What goes through a door but never goes in and never comes out?

I have seas without water. I have forests without wood. I have deserts without sand. I have houses with no brick. What am I?

What has four legs, but can't walk?