On turning up her nest with his plough, November 1785 he writes:

I'm truly sorry Man's dominion
Has broken Nature's social union,
An' justifies that ill opinion,
Which makes thee startle,
At me, thy poor, earth-born companion,
An' fellow-mortal! 

Burns's poem proposes an equality between ploughman and mouse, and this equality can be extrapolated to apply to the human hierarchies that Burns elsewhere challenges directly in political poems such as "Song-For a' that and a' that," which concludes "That Man to Man the warld o'er, Shall be brothers for a' that".

But it is with his poem "To A Mouse" that reveals his two strands of thought that are grounded in attitudes to the natural world.  The reference to Man's dominion' and to natures social union define two strands of thought.  As a ploughman, Burns represents the stewardship of plants and animals.  The ploughman reflects on the damage done by the necessary tilling of the fields and reveals his sensitive understanding that both he and the mouse are fellow citizens of the world which neither has created.  Comparisons are made between the life of a mouse and man and neither is so different and each depends wholly on nature and its order to sustain itself.

Have a great burn's night and save a thought for your environment.