It is able, but not capable.
It can stop, but not go.
It is dead, but not yet perished.
It's a ghost, but not paranormal.
Is it high, or is it low?
Answer: It is high. All of the words that it is have the first two letters consecutive in the alphabet: ab, st, de, gh, and hi.
I am a creature that makes you go "Ick!"
I can literally stop you dead in your tracks.
I'll come out of nowhere and I'll get you quick.
My bite hurts as much as stepping on tacks.
I'm one of the most dangerous desert creatures of all.
People get scared when they see me crawl.
What kind of creature am I?
You can search high, you can search low,
Or follow each point of the compass rose,
But no matter where in the world you go,
It's always there right under your nose.