-field makes a "field" for the worm(s) to eat; -trail causes each worm to leave a trail behind it. You can figure out the rest by yourself.
Snails by Karl Heuer
The lower-right-hand character position will not be updated properly on a terminal that wraps at the right margin.
Terminal initialization is not performed.
Created by unroff & hp-tools. © somebody (See intro for details). All Rights Reserved. Last modified 11/5/97