William Blake's "Auguries of Innocence"

1.  What does the stanza mean?  
2.  How does Blake use a literary device to convey that meaning?

The gnat that sings his summer's song
Poison gets from slander's tongue.
The poison of the snake and newt
Is the sweat of envy's foot.

1. I think that stanza means to show how man kind has given some of nature a bad name
because of their natural abilities and some jealousy because of their behavioral strengths. The animals develop a bad name because of society's constant slander that they are only here to harm, when really they are just protecting themselves.

2. Blake uses Personification by giving the Gnat the ability to sing, which is a human quality. The Gnat sings his summer song to show the serene quality of nature and not the danger society feels it possesses.