Encounter with a slug

How far, Slug, have you belly-walked,

While humans in the garden talked,
To find yourself a well-earned place -
Here on the bottle you now grace,
The very one which, days before,
Brought us fine wine from foreign shore.

We each have taken summer's seat
Upon our patio replete
With verdant folio and flower,
Amidst which you had found your bower.
So as we sat here at our ease,
Out of the Sun, but in the breeze,
You came a-waltzing, if you please.
And clambered quick, though leglessly,
On what was put down carelessly,
Next to your unknown sluggy prescence
Which now, we see, is of the essence
And plays its part in Nature's scheme,
Earning its portion of esteem.

Slug! Are you the lesser for not having legs?
Slug! Do you feel envy when I use my pegs?
To you, we are no more than stimulus,
Which makes us think of you as timorous.
This gap between two worlds will ever be -
Our states are what determine how we see.
Your place with us is in your proper sphere,
Remote from our concerns, and yet so near.
Our guests depart, but you with us remain
And repossess, of right, your just domain.