"To A Louse, On Seeing One on a Lady's Bonnet at Church" is a 1786 Scots language

Scots language

Scots is the Germanic language variety spoken in Lowland Scotland and parts of Ulster . It is sometimes called Lowland Scots to distinguish it from Scottish Gaelic, the Celtic language variety spoken in most of the western Highlands and in the Hebrides.Since there are no universally accepted...

 poem by Robert Burns

Robert Burns

Robert Burns was a Scottish poet and a lyricist. He is widely regarded as the national poet of Scotland, and is celebrated worldwide...

  in his favourite meter, Standard Habbie. The poem's theme is contained in the final verse:

Burns original	Standard English translation
O wad some Pow'r the giftie gie us To see oursels as ithers see us! It wad frae mony a blunder free us, An' foolish notion: What airs in dress an' gait wad lea'e us, An' ev'n devotion!	And would some Power the small gift give us To see ourselves as others see us! It would from many a blunder free us, And foolish notion: What airs in dress and gait would leave us, And even devotion!

In this poem the narrator notices an upper class lady in church, with a louse

Louse

Lice is the common name for over 3,000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents...

 that is roving, unnoticed, around in her bonnet

Bonnet (headgear)

Bonnets are a variety of headgear for both sexes, which have in common only the absence of a brim. Bonnet derives from the same word in French, where it originally indicated a type of material...

. The poet chastises the louse for not realising how important his host is, and then reflects that, to a louse, we are all equal prey, and that we would be disabused of our pretensions if we were to see ourselves through each others' eyes.