Many have heard me riddle

Question: Many have heard me, but nobody has seen me, and I will not speak back until spoken to.What am I?

Question: What do you call a sad bird?

Question: What kinds of balls do dragons play soccer with?

Question: What tastes better than it smells?

Question: What goes in the water black and comes out red?

Question: What loses its head in the morning and gets it back at night?