useless trivia: What Word Means: Aft - Behind?

Questions

The electric eel's shocking power is so great that it can overtake its victims while ----------?

Snails have ----------. They are arranged in rows along the snail's tongue and are used like a file to saw or slice through the snail's foot.?

The electric organs in an electric eel make up four-fifths of its ----------?

So that it can pull its lithe body into a tight, prickly little ball for defense, the hedgehog has a large muscle running along its ----------?

Some ----------?