Why are worms slimy
Worms owe their slimy texture not to what most would feel to be a self-defense mechanism or even their specific environment at any given time but to a primal need for survival. Living deep underground and feeding primarily on plant roots worms have limited access to oxygen, and as such have not developed any lungs to allow for respiration to occur. Nevertheless oxygen is necessary for them to survive, utilizing it in their own fashion to process various chemicals and other substances within their bodies.
Working to take in oxygen through a somewhat unique process of absorption rather than direct respiration the slimy substance on the surface of worms is a form of mucus that actually takes in stray oxygen particles and passes it through to skin of the worm for processing. For this reason if a worm ever becomes too dry and its mucus dried out it will literally die of suffocation due to the inability to process any new oxygen, causing worms to require moist environments rather than arid desert lands.
The mucus found around the worm also works to aid in the worm reproduction process. Although all worms naturally have both male and female sex organs – being able to produce both sperm and eggs simultaneously – sexual reproduction is necessary for new worms to develop. The 32nd and 37th segments of a worm’s body is known as the clitellum and secretes a special form of the standard mucus that allows two separate worms to be literally “glued” together as they mate, functioning to also generate a protective cocoon around new baby worms as they formulate into new adult worms.
As an added bonus the mucus necessary to earthworm survival also works to aid as a lubricant for traveling. Due to their subterranean nature worms must rely heavily upon ease of travel to navigate various tunnels and root systems for survival. The mucus that allows them to both breathe and mate also allows worms to move with greater ease from place to place and as such is a necessity for them – especially during drier times or over some surfaces where travel may be more difficult to accomplish.