Answer:
It rows quickly with four oars but never comes out from under its own roof. What is it?
The Titanic is still here.
The more you have me the less you see. Shine a light on me and I shall flee.
A dragon's tooth in a mortal's hand, I kill, I maim, I divide the land.
I have a small hill with seven holes.
It is an insect, and the first part of its name is the name of another insect. What is it?