Riddle #1206

Question: A trail, a union, together tied.
Come across me and you will find,
you cannot change the course I'm on,
without me you cannot travel on.

What am I?

Question: What kind of mouse does not eat, drink or even walk?

Question: What fish only swims at night?

Question: What has a bed that you can't sleep in?

Question: What tastes better than it smells?

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