Thou saw the fields laid bare an' wast
An' weary Winter comin fast
An' cozie here, beneath the blast
Thou thought to dwell
Till crash! the cruel coulter past
Out thro' thy cell
That wee-bit heap o' leaves an' stibble
Has cost thee monie a weary nibble!
Now thou's turn'd out, for a' thy trouble
But house or hald
To thole the Winter's sleety dribble
An' cranreuch cauld!
But Mousie, thou art no thy-lane
In proving foresight may be vain
The best laid schemes o' Mice an' Men
Gang aft agley
An' lea'e us nought but grief an' pain
For promis'd joy!
Still, thou art blest, compar'd wi' me!
The present only toucheth thee
But Och! I backward cast my e'e
Rough English translation: 
 But little Mouse, you are not alone, In proving foresight may be vain: The best laid schemes of mice and men Go often awry, And leave us nothing but grief and pain, For promised joy! 
 The mouse surely now realizes that not everything can be prepared for, which Burns himself now ponders. We’re meant to realize that just as the mouse’s best laid plans were dashed by a higher power, so might man’s. Even more so, Burns could easily have never noticed the mouse there after he destroyed her house in his field. Just as a higher power may barely notice destroying the life of a human being. 
 The line “The best laid schemes o' Mice an' Men” inspired the title of John Steinbeck’s famous 1937 novel  Of Mice and Men.
To a Mouse