Answer:
I always run but never walk often murmur but never talk have a bed but never sleep has a mouth but never eat.
I am a band that does not perform sing or act.
I go through a door but never go in and never come out.
I am the reaction after enjoying soda.
I will disappear every time you say my name. What am I?
If I say "everything I tell you is a lie", am I telling you the truth or a lie?